All computations performed used0.6as the specific gravity. doc._boomrl = function() { } for (var i=0; i < document.forms.length; i++) { 10 We use cookies to provide you with a better experience. iframe.role = "presentation"; There are different standard conditions for temperature and pressure, so care is taken when choosing a particular standard value. }); The North American Combustion Handbook (3rdEdition 1986) places the specific gravity of natural gas between 0.59 and 0.64. window.ShopifyAnalytics.meta = window.ShopifyAnalytics.meta || {}; Additional variables include,Tbwhich is Standard Temperature or 518.67R, Pb which is Standard Pressure or 14.696 psia,Tis the gas temperature in degrees R; 60F or 519.67R used for this analysis,Sgis the specific gravity of natural gas (air = 1.0), 0.60 used for this analysis,is gas viscosity, 7.0E-06 lbm/ft-sec used for this analysis,Zis the gas compressibility factor, 1.0 for low pressure gas, andis pipe surface roughness in inches ( 0.0018 for steel and 0.00006 for plastic). return; The equations and tables in the NFPA and IFGC provide very comparable values with the ASTM / AGA equations using the Darcy Equation and the Colebrook-White formula forf. SCFM means standard cubic foot per minute which is the volume of the same gas now at standard conditions of temperature and pressure. 11 The inside diameter of each of these pipes is different. var LOADER_TIMEOUT = 3000; } var href = document.links[i].getAttribute('href'); iframeLoader(true); var first = document.getElementsByTagName('script')[0]; These points were compared with answers created when using each of the alternate equations. if (window && window.navigator && typeof window.navigator.sendBeacon === 'function' && typeof window.Blob === 'function' && !Monorail.isIos12()) { Again, as noted above, there is no universally accepted set of normalized or standard conditions. iframe.src = "about:blank"; } // sendBeacon was not successful 9 Table 1:For 2.0 psig (13.8 kPa-g) inlet pressure and 1.0 psig (6.9 kPa-g) drop, using Schedule 40 steel pipe, sizes -inch (DN-15) to 6-inch (DN-150). 
This analysis is for new clean pipe. 5 therms/hr 96.7ft3/therm = 483.5 ft/hr. {shop_id: 15714565, try { Note 1:Formerly, the 2.825 value in equation 5 was 2.51 and is the Colebrook-White equation, 1990. = pipe inside diameter roughness, same units as D. payload: payload, var target = event.target || event.srcElement; (window.gaDevIds=window.gaDevIds||[]).push('BwiEti'); } var eventsListenerScript = document.createElement('script'); }); Note:Reynolds Number Range:8.8E+03 to 6.3E+06. })(); }); P } } var token = match? theme_id: 151568585, window.attachEvent("onload", boomerangSaveLoadTime); } Since the energy in natural gas is equivalent to the gas's volume, you can freely convert between BTUs per hour and cubic feet per minute (CFM). document.cookie = 'loggedConversion=' + token + '; expires=' + twoMonthsFromNow; 
Note:Reynolds Number Range:4.1E+03 to 2.9E+06. (2) If the calculated pressure drop (P1P2) is greater than about 10% but less than 40% of the inlet pressureP1, reasonable accuracy will be obtained if the specific volume used in the formula is based on the averageP1andP2conditions. win = iframe.contentWindow; var blobData = new window.Blob([payload], { var promoted = false; ), ( }; } } this.domain = dom; } metadata: { }; } session_token[1] : "",page_type: "page"};window.navigator.sendBeacon("https://monorail-edge.shopifysvc.com/v1/produce", JSON.stringify({schema_id: "online_store_buyer_site_abandonment/1.1",payload: payload,metadata: {event_created_at_ms: currentMs,event_sent_at_ms: currentMs}}));}}window.addEventListener('pagehide', handle_abandonment_event);}}()); if (window.jQuery) { window.BOOMR.snippetMethod = "p"; These texts all indicate that the Darcy-Weisbach equation appears to be the most accurate method for determining pressure drop, but this method was avoided because of the difficulty of determining the value forf(friction coefficient). iframeStyle.height = 0; PE as well as steel piping were considered for 20 psig gas and 40 psig gas. Table 2:For 3.0 psig (20.7 kPa-g) inlet pressure and 2.0 psig (13.8 kPa-g) drop, using Schedule 40 steel pipe, sizes -inch (DN-15) to 6-inch (DN-150). if(href && href.indexOf('/checkout') >= 0) { if (token) { for (var i = 0; i < trekkie.methods.length; i++) { Note:Reynolds Number Range:2.2E+04 to 5.4E+06. iframeLoader(false); trekkie.ready(function() { link.addEventListener("load", promote); window.ShopifyAnalytics.lib = window.trekkie; It is also important that we discuss the unit of flow measurement in some of these flow meter technologies. 'trackLink' ), ( 4 }, The AGA equations in the AGA Plastic Pipe Manual provide very comparable values with the AGA equations using the Darcy Equation and the Colebrook-White formula forf. if (!promoted) { bootstrap(); 15 });
var linkerParam = tracker.get('linkerParam'); 1 trekkie.methods = [
The straight forward capacity factor for gas is(0.65/0.60)^0.5; this equates to1.04(and approximately1.06whenfis considered). var scriptFallback = document.createElement('script'); Previous articles in this series suggest that either schedule 40 steel pipe or polyethylene pipe (PE) are the normal piping materials used. The most common unit for measuring natural gas is the therm. The basis of the AGA flow equations is an f value that is a function of Reynolds number. trekkie.factory = function(method) { } else if (win.attachEvent) { window.BOOMR_onload = (e && e.timeStamp) || new Date().getTime(); dom = document.domain; type: 'text/plain' if (e.propertyName === "onBoomerangLoaded") { A variation in standard temperature can result in a significant volumetric variation for the same mass flow rate. document.getElementsByTagName('head')[0].appendChild(eventsListenerScript); args.unshift(method); Powered by, ( Higher specific gravity means higher viscosity, lower Reynolds number, and higher value for f. }, ResourceTiming: { try { window.ShopifyAnalytics.merchantGoogleAnalytics.call(this); } catch(error) {}; link.relList.supports("preload") && } console.log(e); typeof link.relList.supports === "function" && var action = document.forms[i].getAttribute('action'); In order to come to some conclusions as to the validity of each of the alternate equations discussed below, a program was set up in Excel and in Visual Basic to calculate the value of f to 5 significant digits, for each flow point, and then solve for flow based on available pressure drop using the equations outlined above (via Darcy-Weisbach formula). ACFM and SCFM. return Monorail.sendRequest("https://" + monorailDomain + "/v1/produce", JSON.stringify(event)); }; }); setTimeout(function() { trekkie.config.initialDocumentCookie = document.cookie; Watch this quick video to see EXACTLY how to calculate the SCFM or SCFH flow rate for a 500,000 BTU/Hr boiler. is in absolute temperature units (i.e., either kelvins or degrees Rankine). where } } else if (document.attachEvent) { script.async = true; isIos12: function isIos12() { addListener(document.links[i], 'click', decorate); var script = document.createElement('script'); Cubic feet per minute (CFM) is an often confusing term because it has no single definition that applies to all instances. scriptFallback.type = 'text/javascript'; event_sent_at_ms: currentMs return false; window.BOOMR.snippetMethod = "s"; window.BOOMR.snippetVersion = 12; The equations can then be rearranged to create a pressure drop calculation, which the engineer can use to backcheck the analysis. } catch (e) { link.as = "script"; function gtag(){dataLayer.push(arguments);} There are two final considerations when applying these formulas: Maximum velocity and actual specific gravity of the natural gas. To calculate the CFM (ft3/min) or CFH (ft3/hr) for 500,000 BTUs per hour of Methane we have: 500,000 BTU/hr 100,000 BTU/therm = 5 therms/hr. ), ( enabled: true, Gases are compressible, which means that a figure in cubic feet per minute cannot necessarily be compared with another figure when it comes the mass of the gas. eventsListenerScript.src = "//cdn.shopify.com/shopifycloud/shopify/assets/shop_events_listener-fa61fd11817b231631d2fe43dc869d0b1d14a06332792d42f1a1d94bda5aa31e.js"; The Mueller and IGT Distribution equations provide higher flow rates and lower pressure drops than might be experienced in actual practice. }, }, Only steel was considered for the lower pressure pipes, since they would likely be installed above grade. Pressure ranges:2 psig inlet with 1 psig drop, 3 psig with a 2 psig drop, 5 psig with a 3.5 psig drop, 20 psig with a 2.0 psig drop; and 40 psig with a 4 psig drop.
There are three flow regimes that are encountered in gas pipes:Laminar Flow, Partially Turbulent Flow, and Fully Turbulent Flow. Degree F = 1.8*C + 32 , F denotes Fahrenheit, C denotes degree celsius, 2009 - 2022 instrumentationtoolbox.com. Our intent is to determine the validity of each equation with respect to flow rates that might be encountered by a plumbing engineer. link.rel = "preload"; script.type = 'text/javascript'; Pipe Materials:Sch 40 steel pipe, SDR 11 PE pipe, SDR 13.5 PE pipe. Equations 2 and 3 have not been corrected to include units. event = event || window.event;
Since a gas occupies different volumes at different conditions of temperature and pressure, gas volumes are specified at some agreed-upon set of pressure and temperature known as standard conditions and the gas volumes referred to as standardized volumetric flow measurement. promoted = true; var script = document.createElement("script"); Selecting the Natural Gas or Methane Mass Flow Meter:1" NPT Natural Gas Flow Meter Thermal Mass Flow. function promote() { iframeStyle.display = "none"; (1)Considerations About Equations for Steady State Flow in Natural Gas Pipelinesby Paulo M. Coelho and Carlos Pinho in the Journal of the Brazilian Society of Mechanical Sciences and Engineering, July-September, 2007;(2)Crane Technical Paper 410, 2018; (3) Chapter 22 of ASTM MNL 58Petroleum Refining and Natural Gas Processing, 2013, concerningTransportation of Crude Oil, Natural Gas, and Petroleum Products. (function () { if (target && (target.getAttribute('action') || target.getAttribute('href'))) { for (var attr in meta) { iframe.title = ""; As a result, these equations are not recommended for typical plumbing applications where higher pressures might be used. Most of the alternate gas flow equations predate the availability of present-day computers. return trekkie; e.detail.BOOMR.t_end = new Date().getTime(); window.BOOMR.themeVersion = "1.0.0"; }
window.BOOMR.snippetExecuted = true; parentNode.appendChild(script); if (window.BOOMR && (window.BOOMR.version || window.BOOMR.snippetExecuted)) { There are many equations for determining the flow in natural gas pipes and the pressure drops associated with those flows, or vice versa. schema_id: schemaId, } 19 setCookieIfConversion(token); In Europe, the standard temperature is most commonly defined as 0C, but not always.
]; if (!e) e=event; T if (win.addEventListener) { ), ( } This has been reviewed in some detail in the ASPE Plumbing Engineering Design Handbook Volume 3, Chapter 11, that will be published in the Spring 2020. script.id = "boomr-scr-as"; The volume of gas after it is pressurized or rarefied is referred to as its "actual" volume. win._boomrl = function() { ); Nominal Pipe Sizes:0.5 (DN-15) thru 6 (DN150) as available. if (jquery) { script.src = window.BOOMR.url; scriptFallback.async = true;
is in absolute pressure units and window.ShopifyAnalytics.meta.currency = 'USD'; Unfortunately, this usually is not the case as the most important change between these two definitions is the pressure.
Subscribe to our newsletters & stay updated, Flow Equations For Low Pressure Natural Gas, Using Pressure Regulators for Site Distribution in Natural Gas Pipelines, Natural Gas Pipeline Systems On Site Distribution, F.W. window.BOOMR.url = scriptFallback.src = 'https://cdn.shopify.com/s/trekkie.storefront.c8a4b74b81390ab4b5fd7522cfda0ce4acf129c5.min.js'; trekkie.config = config || {}; We Provide Tools and Basic Information for Learning Process Instrumentation and Control Engineering.
Clean pipe will not affect the Partially Turbulent flow regime, since the flow at the pipe surface is laminar. var key = trekkie.methods[i]; } var event = { function iframeLoader(wasFallback) { if (document.addEventListener) { }, LOADER_TIMEOUT); parent.appendChild(script); xhr.send(payload); } else if (window.Checkout && window.Checkout.$) { var originalDocumentWrite = document.write; It is related to the mass flow rate of the gas by a multiplicative constant which depends only on the molecular weight of the gas. ), Learning Instrumentation And Control Engineering, Industrial Motor Starters and Starting Methods, Electrical Protection of 3 phase Motors: Types and Protection Schemes, Understanding the Technical Specifications on the Nameplate of Solar Panels, A Guide to Solar Panels Power Installations, How to Specify Electric Motors for Hazardous Locations, Understanding Battery Technical Specifications, Instrumentation Books for Instrument Engineers and Technicians, Sizing Orifice Plates with Daniel Flow Calculator. 'trekkie_storefront_load_errors/1.1', Note:Reynolds Number Range:4.2E+04 to 1.0E+07. var where = document.currentScript || document.getElementsByTagName("script")[0]; Table 3:For 5.0 psig (34.5 kPa-g) inlet pressure and 3.5 psig (24.1 kPa-g) drop, using Schedule 40 steel pipe, sizes -inch (DN-15) to 6-inch (DN-150). window.ShopifyAnalytics.merchantGoogleAnalytics = function() { var currentMs = new Date().getTime(); }); return function() { }; ), ( var dom, bootstrap, iframe, iframeStyle; ), ( return false; Furthermore, there is no standard for what the inlet pressure to these pipes might be and what the expected pressure drops might be.
} 5 document.cookie = '_shopify_ga=' + linkerParam + '; ' + 'path=/'; jquery = window.Checkout.$; iframe.loading = "eager"; match[1]: undefined; In the United States, the standard temperature is most commonly defined as 60F or 70F, but again, not always. standard conditions for temperature and pressure, Standard conditions for temperature and pressure, ACFM versus SCFM for ASME AG-1 HEPA Filters, SCFM (Standard CFM) vs. ACFM (Actual CFM), https://en.wikipedia.org/w/index.php?title=Standard_cubic_feet_per_minute&oldid=1096617906, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 5 July 2022, at 16:36. Again, the fan will pump the same volume, though not mass, at any other air density. } else if (window.attachEvent) { (function(){if ("sendBeacon" in navigator && "performance" in window) {var session_token = document.cookie.match(/_shopify_s=([^;]*)/);function handle_abandonment_event(e) {var entries = performance.getEntries().filter(function(entry) {return /monorail-edge.shopifysvc.com/.test(entry.name);});if (!window.abandonment_tracked && entries.length === 0) {window.abandonment_tracked = true;var currentMs = Date.now();var navigation_start = performance.timing.navigationStart;var payload = {shop_id: 15714565,url: window.location.href,navigation_start,duration: currentMs - navigation_start,session_token: session_token && session_token.length === 2 ? BOOMR_lstart = new Date().getTime(); xhr.setRequestHeader('Content-Type', 'text/plain'); 22 gtag('js', new Date()); function addListener(element, type, callback) { One cubic meter of gas at high a pressure and temperature inside a process vessel will not occupy one cubic meter under different pressure and temperature conditions in the same vessel. "https://cdn.shopify.com/shopifycloud/boomerang/shopify-boomerang-1.0.0.min.js"; {"Trekkie":{"appName":"storefront","development":false,"defaultAttributes":{"shopId":15714565,"isMerchantRequest":null,"themeId":151568585,"themeCityHash":"60531518256165055","contentLanguage":"en","currency":"USD"},"isServerSideCookieWritingEnabled":true},"Google Analytics":{"trackingId":"UA-106835803-1","domain":"auto","siteSpeedSampleRate":"10","enhancedEcommerce":true,"doubleClick":true,"includeSearch":true},"Facebook Pixel":{"pixelIds":["2190101541151852"],"agent":"plshopify1.2"},"Google Gtag Pixel":{"conversionId":"0","eventLabels":[{"type":"page_view","action_label":"AW-795007018\/frY8CMDQuIcBEKqwi_sC"},{"type":"purchase","action_label":"AW-795007018\/C61VCMPQuIcBEKqwi_sC"},{"type":"view_item","action_label":"AW-795007018\/eVELCOrTuIcBEKqwi_sC"},{"type":"add_to_cart","action_label":"AW-795007018\/cgvPCO3TuIcBEKqwi_sC"},{"type":"begin_checkout","action_label":"AW-795007018\/kSK9CPDTuIcBEKqwi_sC"},{"type":"search","action_label":"AW-795007018\/Afm6CPPTuIcBEKqwi_sC"},{"type":"add_payment_info","action_label":"AW-795007018\/f5RzCPbTuIcBEKqwi_sC"}],"targetCountry":"US"},"Session Attribution":{},"S2S":{"emitV4CheckoutEvent":true,"facebookCapiEnabled":true,"facebookAppPixelId":"2190101541151852","source":"trekkie-storefront-renderer"}} This is not the same as pumping a constant mass of air. 'track', } iframeLoader(true); The classic equation for Reynold number is: Re= V D /(Equation 2), = dynamic viscosity 7E-06 lbm/ft-sec(0.010392 centipoise). An alternate would be to break the length of pipe into several segments that meet the conditions above using the outlet pressure of segment1as the inlet pressure to segment2, and so forth. {\displaystyle P} This is only valid when at a pressure and temperature close to standard conditions. (function () { window.BOOMR.themeName = "Debut"; Various standard conditions exist for determining standardized flow rates in most custody transfer applications for gases around the world especially natural gas: (a) API (American Petroleum Institute) uses 14.7PSIA and 60 degree Fahrenheit equivalent to 519.67 degree Rankine as their standard conditions for calculating gas volumetric flow rates, (b) ASME (American Society of Mechanical Engineers) uses 14.7 PSIA and 68 degrees Fahrenheit (527.67 degrees Rankine) as their standard conditions for calculating. } bootstrap(parentNode, "boomr-async"); script.onerror = function(e) { element.addEventListener(type, callback); In other words, a gas will yield to an increasing pressure by decreasing in volume as the gas molecules are forced closer together, and it will yield to a decreasing temperature by decreasing in volume as the kinetic energy of the individual molecules is reduced.
return true; So, there are no standardized tables for higher pressure conditions that exceed pressures outlined in NFPA 54 National Fuel Gas Code and the ICC International Fuel Gas Code. producer_url: "https://monorail-edge.shopifysvc.com/v1/produce", ga(function (tracker) { } win = iframe.contentWindow;
return; iframeStyle.border = 0; (3) If the calculated pressure drop (P1P2) is greater than about 40% of the inlet pressureP1, then different high pressure drop formulas are provided. }); var twoMonthsFromNow = new Date(Date.now()); Equations used:NFPA/IFGC equation, Mueller Equation, Weymouth Equation, IGT Distribution Equation, Spitzglass-High Pressure Equation, and AGA Plastic Pipe Manual Equations. A maximum actual gas velocity of 100 feet per second (30.5 meters per second) should be considered for gas pressures over 10 psig (69.0 kPa-g). Calculatingfinvolves an iterative process since the square root offis part of the denominator on both sides of the equation forf. iframe.src = "javascript:var d=document.open();d.domain='" + dom + "';void(0);";
if (link.relList && 'trackForm', When a vacuum is applied to a standard cubic foot of gas, it expands. The other consideration in this discussion is maximum velocity. event_created_at_ms: currentMs, We can use the ideal gas equation to determine this: Since we know that the definition of volumetric flow (Q) is volume over time (V/t), we may divide each Volume ,V, variable by t to convert this into a volumetric flow rate thus: The above equation gives us the ratio of standardized volumetric flow rate (Qs) to actual volumetric flow rate (Q), for any known pressures and temperatures. return; For lower pressure piping, the values in the NFPA/IFGC tables were also compared. ResourceTiming: { A maximum gas velocity of 100 feet per second (30.5 meters per second) to minimize noise and erosion. if (dom) { ), ( 3" Natural Gas Flow Meter 3" ANSI Vortex. } SCF and ACF for an ideal gas are related in accordance with the combined gas law:[1][2][3], Defining standard conditions by the subscript 1 and actual conditions by the subscript 2, then:[1][2][4]. The internet places the specific gravity of natural gas between0.6and0.7. The Darcy-Weisbach equation is as follows: hL= f()(Equation 1), Where:hL= gas head loss in feet (meters) of fluid in this case gas, f =friction flow coefficient - dimensionless, D= internal diameter of the pipe, same units as L, V= gas velocity in feet per second (meters per second), g= gravitational constant 32.174 feet per second^2 (9.806 meters per second^2). BOOMR_lstart = new Date().getTime(); sendRequest: function sendRequest(endpointUrl, payload) { Worldwide, the "standard" condition for pressure is variously defined as an absolute pressure of 101,325 pascals (Atmospheric pressure), 1.0 bar (i.e., 100,000 pascals), 14.73psia, or 14.696psia and the "standard" temperature is variously defined as 68F, 60F, 0C, 15C, 20C, or 25C. ), ( if(action && action.indexOf('/cart') >= 0) { if (promoted) { Considerations are noise and erosion.
2 var customDocumentWrite = function(content) { var jquery = null; window.addEventListener("load", boomerangSaveLoadTime, false); return; if (trekkie.integrations) { For example, a mass flow rate of 1,000kg/h of air at 1 atmosphere of absolute pressure is 455SCFM when defined at 32F (0C) but 481SCFM when defined at 60F (16C). try { var link = document.createElement("link"); trekkie.push(args); } else { }; e.detail.BOOMR.t_end = new Date().getTime(); promoted = true;
if (!hasLoggedConversion(token)) { script.id = scriptId || "boomr-if-as"; addListener(window, 'load', function(){ source_url: "https://cdn.shopify.com/s/trekkie.storefront.c8a4b74b81390ab4b5fd7522cfda0ce4acf129c5.min.js"}); } ), ( jquery = window.jQuery; On this blog, we have discussed in the past various flow meter technologies where a volumetric flow rate is required. if (window.addEventListener) { Actual cubic foot per minute (ACFM) is the volume of gas flowing anywhere in a system, taking into account its temperature and pressure. } xhr.open('POST', endpointUrl); Here, ACFM means actual cubic foot per minute which is the volume of the gas at the flowing conditions. Distances:10 feet (3 meters) to 2,000 feet (610 meters) in increments similar to NFPA 54 and IFGC. loaded = true; } For all of the following equations,Qhis flow in SCFH,P1is the inlet pressure,P2is the outlet pressure,Dis the pipe inside diameter in inches, Sg is the specific gravity, andLis the length of the pipe segment in feet. if (window.navigator.sendBeacon(endpointUrl, blobData)) { iframe = document.createElement("IFRAME"); context_url: window.location.href, 'page', jquery('body').append(content);
This analysis is for new clean pipe. 5 therms/hr 96.7ft3/therm = 483.5 ft/hr. {shop_id: 15714565, try { Note 1:Formerly, the 2.825 value in equation 5 was 2.51 and is the Colebrook-White equation, 1990. = pipe inside diameter roughness, same units as D. payload: payload, var target = event.target || event.srcElement; (window.gaDevIds=window.gaDevIds||[]).push('BwiEti'); } var eventsListenerScript = document.createElement('script'); }); Note:Reynolds Number Range:8.8E+03 to 6.3E+06. })(); }); P } } var token = match? theme_id: 151568585, window.attachEvent("onload", boomerangSaveLoadTime); } Since the energy in natural gas is equivalent to the gas's volume, you can freely convert between BTUs per hour and cubic feet per minute (CFM). document.cookie = 'loggedConversion=' + token + '; expires=' + twoMonthsFromNow; Note:Reynolds Number Range:4.1E+03 to 2.9E+06. (2) If the calculated pressure drop (P1P2) is greater than about 10% but less than 40% of the inlet pressureP1, reasonable accuracy will be obtained if the specific volume used in the formula is based on the averageP1andP2conditions. win = iframe.contentWindow; var blobData = new window.Blob([payload], { var promoted = false; ), ( }; } } this.domain = dom; } metadata: { }; } session_token[1] : "",page_type: "page"};window.navigator.sendBeacon("https://monorail-edge.shopifysvc.com/v1/produce", JSON.stringify({schema_id: "online_store_buyer_site_abandonment/1.1",payload: payload,metadata: {event_created_at_ms: currentMs,event_sent_at_ms: currentMs}}));}}window.addEventListener('pagehide', handle_abandonment_event);}}()); if (window.jQuery) { window.BOOMR.snippetMethod = "p"; These texts all indicate that the Darcy-Weisbach equation appears to be the most accurate method for determining pressure drop, but this method was avoided because of the difficulty of determining the value forf(friction coefficient). iframeStyle.height = 0; PE as well as steel piping were considered for 20 psig gas and 40 psig gas. Table 2:For 3.0 psig (20.7 kPa-g) inlet pressure and 2.0 psig (13.8 kPa-g) drop, using Schedule 40 steel pipe, sizes -inch (DN-15) to 6-inch (DN-150). if(href && href.indexOf('/checkout') >= 0) { if (token) { for (var i = 0; i < trekkie.methods.length; i++) { Note:Reynolds Number Range:2.2E+04 to 5.4E+06. iframeLoader(false); trekkie.ready(function() { link.addEventListener("load", promote); window.ShopifyAnalytics.lib = window.trekkie; It is also important that we discuss the unit of flow measurement in some of these flow meter technologies. 'trackLink' ), ( 4 }, The AGA equations in the AGA Plastic Pipe Manual provide very comparable values with the AGA equations using the Darcy Equation and the Colebrook-White formula forf. if (!promoted) { bootstrap(); 15 }); var linkerParam = tracker.get('linkerParam'); 1 trekkie.methods = [
The straight forward capacity factor for gas is(0.65/0.60)^0.5; this equates to1.04(and approximately1.06whenfis considered). var scriptFallback = document.createElement('script'); Previous articles in this series suggest that either schedule 40 steel pipe or polyethylene pipe (PE) are the normal piping materials used. The most common unit for measuring natural gas is the therm. The basis of the AGA flow equations is an f value that is a function of Reynolds number. trekkie.factory = function(method) { } else if (win.attachEvent) { window.BOOMR_onload = (e && e.timeStamp) || new Date().getTime(); dom = document.domain; type: 'text/plain' if (e.propertyName === "onBoomerangLoaded") { A variation in standard temperature can result in a significant volumetric variation for the same mass flow rate. document.getElementsByTagName('head')[0].appendChild(eventsListenerScript); args.unshift(method); Powered by, ( Higher specific gravity means higher viscosity, lower Reynolds number, and higher value for f. }, ResourceTiming: { try { window.ShopifyAnalytics.merchantGoogleAnalytics.call(this); } catch(error) {}; link.relList.supports("preload") && } console.log(e); typeof link.relList.supports === "function" && var action = document.forms[i].getAttribute('action'); In order to come to some conclusions as to the validity of each of the alternate equations discussed below, a program was set up in Excel and in Visual Basic to calculate the value of f to 5 significant digits, for each flow point, and then solve for flow based on available pressure drop using the equations outlined above (via Darcy-Weisbach formula). ACFM and SCFM. return Monorail.sendRequest("https://" + monorailDomain + "/v1/produce", JSON.stringify(event)); }; }); setTimeout(function() { trekkie.config.initialDocumentCookie = document.cookie; Watch this quick video to see EXACTLY how to calculate the SCFM or SCFH flow rate for a 500,000 BTU/Hr boiler. is in absolute temperature units (i.e., either kelvins or degrees Rankine). where } } else if (document.attachEvent) { script.async = true; isIos12: function isIos12() { addListener(document.links[i], 'click', decorate); var script = document.createElement('script'); Cubic feet per minute (CFM) is an often confusing term because it has no single definition that applies to all instances. scriptFallback.type = 'text/javascript'; event_sent_at_ms: currentMs return false; window.BOOMR.snippetMethod = "s"; window.BOOMR.snippetVersion = 12; The equations can then be rearranged to create a pressure drop calculation, which the engineer can use to backcheck the analysis. } catch (e) { link.as = "script"; function gtag(){dataLayer.push(arguments);} There are two final considerations when applying these formulas: Maximum velocity and actual specific gravity of the natural gas. To calculate the CFM (ft3/min) or CFH (ft3/hr) for 500,000 BTUs per hour of Methane we have: 500,000 BTU/hr 100,000 BTU/therm = 5 therms/hr. ), ( enabled: true, Gases are compressible, which means that a figure in cubic feet per minute cannot necessarily be compared with another figure when it comes the mass of the gas. eventsListenerScript.src = "//cdn.shopify.com/shopifycloud/shopify/assets/shop_events_listener-fa61fd11817b231631d2fe43dc869d0b1d14a06332792d42f1a1d94bda5aa31e.js"; The Mueller and IGT Distribution equations provide higher flow rates and lower pressure drops than might be experienced in actual practice. }, }, Only steel was considered for the lower pressure pipes, since they would likely be installed above grade. Pressure ranges:2 psig inlet with 1 psig drop, 3 psig with a 2 psig drop, 5 psig with a 3.5 psig drop, 20 psig with a 2.0 psig drop; and 40 psig with a 4 psig drop.
There are three flow regimes that are encountered in gas pipes:Laminar Flow, Partially Turbulent Flow, and Fully Turbulent Flow. Degree F = 1.8*C + 32 , F denotes Fahrenheit, C denotes degree celsius, 2009 - 2022 instrumentationtoolbox.com. Our intent is to determine the validity of each equation with respect to flow rates that might be encountered by a plumbing engineer. link.rel = "preload"; script.type = 'text/javascript'; Pipe Materials:Sch 40 steel pipe, SDR 11 PE pipe, SDR 13.5 PE pipe. Equations 2 and 3 have not been corrected to include units. event = event || window.event;
Since a gas occupies different volumes at different conditions of temperature and pressure, gas volumes are specified at some agreed-upon set of pressure and temperature known as standard conditions and the gas volumes referred to as standardized volumetric flow measurement. promoted = true; var script = document.createElement("script"); Selecting the Natural Gas or Methane Mass Flow Meter:1" NPT Natural Gas Flow Meter Thermal Mass Flow. function promote() { iframeStyle.display = "none"; (1)Considerations About Equations for Steady State Flow in Natural Gas Pipelinesby Paulo M. Coelho and Carlos Pinho in the Journal of the Brazilian Society of Mechanical Sciences and Engineering, July-September, 2007;(2)Crane Technical Paper 410, 2018; (3) Chapter 22 of ASTM MNL 58Petroleum Refining and Natural Gas Processing, 2013, concerningTransportation of Crude Oil, Natural Gas, and Petroleum Products. (function () { if (target && (target.getAttribute('action') || target.getAttribute('href'))) { for (var attr in meta) { iframe.title = ""; As a result, these equations are not recommended for typical plumbing applications where higher pressures might be used. Most of the alternate gas flow equations predate the availability of present-day computers. return trekkie; e.detail.BOOMR.t_end = new Date().getTime(); window.BOOMR.themeVersion = "1.0.0"; }
window.BOOMR.snippetExecuted = true; parentNode.appendChild(script); if (window.BOOMR && (window.BOOMR.version || window.BOOMR.snippetExecuted)) { There are many equations for determining the flow in natural gas pipes and the pressure drops associated with those flows, or vice versa. schema_id: schemaId, } 19 setCookieIfConversion(token); In Europe, the standard temperature is most commonly defined as 0C, but not always. ]; if (!e) e=event; T if (win.addEventListener) { ), ( } This has been reviewed in some detail in the ASPE Plumbing Engineering Design Handbook Volume 3, Chapter 11, that will be published in the Spring 2020. script.id = "boomr-scr-as"; The volume of gas after it is pressurized or rarefied is referred to as its "actual" volume. win._boomrl = function() { ); Nominal Pipe Sizes:0.5 (DN-15) thru 6 (DN150) as available. if (jquery) { script.src = window.BOOMR.url; scriptFallback.async = true;
is in absolute pressure units and window.ShopifyAnalytics.meta.currency = 'USD'; Unfortunately, this usually is not the case as the most important change between these two definitions is the pressure.
Subscribe to our newsletters & stay updated, Flow Equations For Low Pressure Natural Gas, Using Pressure Regulators for Site Distribution in Natural Gas Pipelines, Natural Gas Pipeline Systems On Site Distribution, F.W. window.BOOMR.url = scriptFallback.src = 'https://cdn.shopify.com/s/trekkie.storefront.c8a4b74b81390ab4b5fd7522cfda0ce4acf129c5.min.js'; trekkie.config = config || {}; We Provide Tools and Basic Information for Learning Process Instrumentation and Control Engineering.
Clean pipe will not affect the Partially Turbulent flow regime, since the flow at the pipe surface is laminar. var key = trekkie.methods[i]; } var event = { function iframeLoader(wasFallback) { if (document.addEventListener) { }, LOADER_TIMEOUT); parent.appendChild(script); xhr.send(payload); } else if (window.Checkout && window.Checkout.$) { var originalDocumentWrite = document.write; It is related to the mass flow rate of the gas by a multiplicative constant which depends only on the molecular weight of the gas. ), Learning Instrumentation And Control Engineering, Industrial Motor Starters and Starting Methods, Electrical Protection of 3 phase Motors: Types and Protection Schemes, Understanding the Technical Specifications on the Nameplate of Solar Panels, A Guide to Solar Panels Power Installations, How to Specify Electric Motors for Hazardous Locations, Understanding Battery Technical Specifications, Instrumentation Books for Instrument Engineers and Technicians, Sizing Orifice Plates with Daniel Flow Calculator. 'trekkie_storefront_load_errors/1.1', Note:Reynolds Number Range:4.2E+04 to 1.0E+07. var where = document.currentScript || document.getElementsByTagName("script")[0]; Table 3:For 5.0 psig (34.5 kPa-g) inlet pressure and 3.5 psig (24.1 kPa-g) drop, using Schedule 40 steel pipe, sizes -inch (DN-15) to 6-inch (DN-150). window.ShopifyAnalytics.merchantGoogleAnalytics = function() { var currentMs = new Date().getTime(); }); return function() { }; ), ( var dom, bootstrap, iframe, iframeStyle; ), ( return false; Furthermore, there is no standard for what the inlet pressure to these pipes might be and what the expected pressure drops might be.
} 5 document.cookie = '_shopify_ga=' + linkerParam + '; ' + 'path=/'; jquery = window.Checkout.$; iframe.loading = "eager"; match[1]: undefined; In the United States, the standard temperature is most commonly defined as 60F or 70F, but again, not always. standard conditions for temperature and pressure, Standard conditions for temperature and pressure, ACFM versus SCFM for ASME AG-1 HEPA Filters, SCFM (Standard CFM) vs. ACFM (Actual CFM), https://en.wikipedia.org/w/index.php?title=Standard_cubic_feet_per_minute&oldid=1096617906, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 5 July 2022, at 16:36. Again, the fan will pump the same volume, though not mass, at any other air density. } else if (window.attachEvent) { (function(){if ("sendBeacon" in navigator && "performance" in window) {var session_token = document.cookie.match(/_shopify_s=([^;]*)/);function handle_abandonment_event(e) {var entries = performance.getEntries().filter(function(entry) {return /monorail-edge.shopifysvc.com/.test(entry.name);});if (!window.abandonment_tracked && entries.length === 0) {window.abandonment_tracked = true;var currentMs = Date.now();var navigation_start = performance.timing.navigationStart;var payload = {shop_id: 15714565,url: window.location.href,navigation_start,duration: currentMs - navigation_start,session_token: session_token && session_token.length === 2 ? BOOMR_lstart = new Date().getTime(); xhr.setRequestHeader('Content-Type', 'text/plain'); 22 gtag('js', new Date()); function addListener(element, type, callback) { One cubic meter of gas at high a pressure and temperature inside a process vessel will not occupy one cubic meter under different pressure and temperature conditions in the same vessel. "https://cdn.shopify.com/shopifycloud/boomerang/shopify-boomerang-1.0.0.min.js"; {"Trekkie":{"appName":"storefront","development":false,"defaultAttributes":{"shopId":15714565,"isMerchantRequest":null,"themeId":151568585,"themeCityHash":"60531518256165055","contentLanguage":"en","currency":"USD"},"isServerSideCookieWritingEnabled":true},"Google Analytics":{"trackingId":"UA-106835803-1","domain":"auto","siteSpeedSampleRate":"10","enhancedEcommerce":true,"doubleClick":true,"includeSearch":true},"Facebook Pixel":{"pixelIds":["2190101541151852"],"agent":"plshopify1.2"},"Google Gtag Pixel":{"conversionId":"0","eventLabels":[{"type":"page_view","action_label":"AW-795007018\/frY8CMDQuIcBEKqwi_sC"},{"type":"purchase","action_label":"AW-795007018\/C61VCMPQuIcBEKqwi_sC"},{"type":"view_item","action_label":"AW-795007018\/eVELCOrTuIcBEKqwi_sC"},{"type":"add_to_cart","action_label":"AW-795007018\/cgvPCO3TuIcBEKqwi_sC"},{"type":"begin_checkout","action_label":"AW-795007018\/kSK9CPDTuIcBEKqwi_sC"},{"type":"search","action_label":"AW-795007018\/Afm6CPPTuIcBEKqwi_sC"},{"type":"add_payment_info","action_label":"AW-795007018\/f5RzCPbTuIcBEKqwi_sC"}],"targetCountry":"US"},"Session Attribution":{},"S2S":{"emitV4CheckoutEvent":true,"facebookCapiEnabled":true,"facebookAppPixelId":"2190101541151852","source":"trekkie-storefront-renderer"}} This is not the same as pumping a constant mass of air. 'track', } iframeLoader(true); The classic equation for Reynold number is: Re= V D /(Equation 2), = dynamic viscosity 7E-06 lbm/ft-sec(0.010392 centipoise). An alternate would be to break the length of pipe into several segments that meet the conditions above using the outlet pressure of segment1as the inlet pressure to segment2, and so forth. {\displaystyle P} This is only valid when at a pressure and temperature close to standard conditions. (function () { window.BOOMR.themeName = "Debut"; Various standard conditions exist for determining standardized flow rates in most custody transfer applications for gases around the world especially natural gas: (a) API (American Petroleum Institute) uses 14.7PSIA and 60 degree Fahrenheit equivalent to 519.67 degree Rankine as their standard conditions for calculating gas volumetric flow rates, (b) ASME (American Society of Mechanical Engineers) uses 14.7 PSIA and 68 degrees Fahrenheit (527.67 degrees Rankine) as their standard conditions for calculating. } bootstrap(parentNode, "boomr-async"); script.onerror = function(e) { element.addEventListener(type, callback); In other words, a gas will yield to an increasing pressure by decreasing in volume as the gas molecules are forced closer together, and it will yield to a decreasing temperature by decreasing in volume as the kinetic energy of the individual molecules is reduced. return true; So, there are no standardized tables for higher pressure conditions that exceed pressures outlined in NFPA 54 National Fuel Gas Code and the ICC International Fuel Gas Code. producer_url: "https://monorail-edge.shopifysvc.com/v1/produce", ga(function (tracker) { } win = iframe.contentWindow;
return; iframeStyle.border = 0; (3) If the calculated pressure drop (P1P2) is greater than about 40% of the inlet pressureP1, then different high pressure drop formulas are provided. }); var twoMonthsFromNow = new Date(Date.now()); Equations used:NFPA/IFGC equation, Mueller Equation, Weymouth Equation, IGT Distribution Equation, Spitzglass-High Pressure Equation, and AGA Plastic Pipe Manual Equations. A maximum actual gas velocity of 100 feet per second (30.5 meters per second) should be considered for gas pressures over 10 psig (69.0 kPa-g). Calculatingfinvolves an iterative process since the square root offis part of the denominator on both sides of the equation forf. iframe.src = "javascript:var d=document.open();d.domain='" + dom + "';void(0);";
if (link.relList && 'trackForm', When a vacuum is applied to a standard cubic foot of gas, it expands. The other consideration in this discussion is maximum velocity. event_created_at_ms: currentMs, We can use the ideal gas equation to determine this: Since we know that the definition of volumetric flow (Q) is volume over time (V/t), we may divide each Volume ,V, variable by t to convert this into a volumetric flow rate thus: The above equation gives us the ratio of standardized volumetric flow rate (Qs) to actual volumetric flow rate (Q), for any known pressures and temperatures. return; For lower pressure piping, the values in the NFPA/IFGC tables were also compared. ResourceTiming: { A maximum gas velocity of 100 feet per second (30.5 meters per second) to minimize noise and erosion. if (dom) { ), ( 3" Natural Gas Flow Meter 3" ANSI Vortex. } SCF and ACF for an ideal gas are related in accordance with the combined gas law:[1][2][3], Defining standard conditions by the subscript 1 and actual conditions by the subscript 2, then:[1][2][4]. The internet places the specific gravity of natural gas between0.6and0.7. The Darcy-Weisbach equation is as follows: hL= f()(Equation 1), Where:hL= gas head loss in feet (meters) of fluid in this case gas, f =friction flow coefficient - dimensionless, D= internal diameter of the pipe, same units as L, V= gas velocity in feet per second (meters per second), g= gravitational constant 32.174 feet per second^2 (9.806 meters per second^2). BOOMR_lstart = new Date().getTime(); sendRequest: function sendRequest(endpointUrl, payload) { Worldwide, the "standard" condition for pressure is variously defined as an absolute pressure of 101,325 pascals (Atmospheric pressure), 1.0 bar (i.e., 100,000 pascals), 14.73psia, or 14.696psia and the "standard" temperature is variously defined as 68F, 60F, 0C, 15C, 20C, or 25C. ), ( if(action && action.indexOf('/cart') >= 0) { if (promoted) { Considerations are noise and erosion.
2 var customDocumentWrite = function(content) { var jquery = null; window.addEventListener("load", boomerangSaveLoadTime, false); return; if (trekkie.integrations) { For example, a mass flow rate of 1,000kg/h of air at 1 atmosphere of absolute pressure is 455SCFM when defined at 32F (0C) but 481SCFM when defined at 60F (16C). try { var link = document.createElement("link"); trekkie.push(args); } else { }; e.detail.BOOMR.t_end = new Date().getTime(); promoted = true;
if (!hasLoggedConversion(token)) { script.id = scriptId || "boomr-if-as"; addListener(window, 'load', function(){ source_url: "https://cdn.shopify.com/s/trekkie.storefront.c8a4b74b81390ab4b5fd7522cfda0ce4acf129c5.min.js"}); } ), ( jquery = window.jQuery; On this blog, we have discussed in the past various flow meter technologies where a volumetric flow rate is required. if (window.addEventListener) { Actual cubic foot per minute (ACFM) is the volume of gas flowing anywhere in a system, taking into account its temperature and pressure. } xhr.open('POST', endpointUrl); Here, ACFM means actual cubic foot per minute which is the volume of the gas at the flowing conditions. Distances:10 feet (3 meters) to 2,000 feet (610 meters) in increments similar to NFPA 54 and IFGC. loaded = true; } For all of the following equations,Qhis flow in SCFH,P1is the inlet pressure,P2is the outlet pressure,Dis the pipe inside diameter in inches, Sg is the specific gravity, andLis the length of the pipe segment in feet. if (window.navigator.sendBeacon(endpointUrl, blobData)) { iframe = document.createElement("IFRAME"); context_url: window.location.href, 'page', jquery('body').append(content);