Check Valve Information   Swing check valve. Wafer check valve. Ball check valve. Image Credit: Cameron | Cameron | KSB AG   Check valves are self-activating safety valves that permit gases and liquids to flow in only one direction. The purpose of a check valve is to prevent process flow from reversing in the system which could damage equipment or upset the process. They are classified as one-way directional valves. Check valves are commonly...
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Q & A on Check Valves

We asked our users for their input on Check Valves. Here are the results of 105 users familiar with Check Valves.

Who Took Our Poll? | Design Trends | Applications and Use | Features | Buying Advice

Who Took Our Poll?Top

Design TrendsTop

Q:
What new technologies are influencing check valve design?
13 answers
Answers:
Those which generate less loss through the valve, improving sealing materials and sealing devices, lighter materials.
~Alfredo Rendueles, Engineering Consultant, Maracaibo, Venezuela
Inline sprint checks used as pressure safety valves, spring checks used as back pressure on metering pumps.
~David F, Project Manager, San Diego, CA
Improved closing coefficient and anti-slam features of needle valves.
~Nic T, Research & Development, Johannesburg, South Africa
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Q:
From your perspective, which companies are creating the most innovative check valves?
13 answers
Answers:
There are many manufacturers and it is difficult to mention one, because each one has particular innovatives which are different from each other, each one with its advantages.
~Alfredo Rendueles, Engineering Consultant, Maracaibo, Venezuela
I seek innovative ways to deliver my projects, I can see little evidence of innovation in design right now.
~Steve B, Engineering Consultant, Barnetby, UK
Not much change recently, unless the elastomers are considered.
~Mark C, Marketing/Sales, Farmington, NM
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Applications and UseTop

Q:
What are some of the applications you have used check valves for?
26 answers
Answers:
To allow self tensioning assemblies, with a spring maintaining contact between the tensioning bolt and the shoe, such that when thermal expansion occurs, the mechanical resistance through contact is maintained. The hydraulic cylinder allows this expansion process, but on shock loading will present a firm resistance. When the shock load dissipates, the check valve releases allowing slow acting flows in both directions.
~Steve B, Engineering Consultant, Barnetby, UK
Sterile oxygen injection to fermenters, inline sulfuric acid injection, hypochlorite inline injection, sterile air, high pressure DI seal water, sanitary process, utilities steam, chilled, cooling, pump discharge
~David F, Project Manager, San Diego, CA
Refinery storage tank, Floating Roof center sump drain, connected to flexible hose inside tank and then connected to exterior nozzle and drained via attached piping.
~Rocky S, Design Engineer, Irvine, CA
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Q:
Please share with us any “non-standard” applications that check valves have been used for.
9 answers
Answers:
PSV's (using spring values of checks as pressure safety valve release points in tubing (1/2") lines and sterilizers Create back pressure for diaphragm pumps (reseat balls on pump) Venting of gases on seal pots (floating balls, lighter that water will float and seat when water fills). Installing well upstream away from injection site to keep check valve clean yet use the non compressibility factor of the fluid to enable hard seating. Back Flow preventers and testing (standard, however special engineered check valve installation with test cocks and procedures to confirm operation)
~David F, Project Manager, San Diego, CA
The old application in hydraulic rams (pumps) should be re-looked at using computational fluid dynamic (CFD) modelling
~Nic T, Research & Development, Johannesburg, South Africa
6" pump discharge flowing right into a 12" check. 2 were destroyed in less than 30 days. Engineering Anyone???!!!
~Mark C, Marketing/Sales, Farmington, NM
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Q:
Do you know of any disastrous mistakes that occurred due to the incorrect usage of check valves?
9 answers
Answers:
Beer getting into steam system and into boiler feed water, foaming and carry over in steam systems. Entire header needed to be isolated (10") to repair 3/8" check valve (no isolation, not correct materials).
~David F, Project Manager, San Diego, CA
Manufacturer finished product with flow arrow in the wrong direction. If you think every valve is QA'd, think again. Do your own checking and double checking. The life you save may be your son's.
~Mark C, Marketing/Sales, Farmington, NM
Twin plate spring return check valves placed in wrong location such that turbulence in the media caused the valve to "chatter" and ultimately self destruct.
~Bob C, Design Engineer, Sheffield, UK
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FeaturesTop

Q:
What would your design or feature "wish list" be for this product?
14 answers
Answers:
Soft goods suitable for steam sterilization temperatures, materials for lactic acid, sulfuric and sodium hypochlorite, clean sterilizable design for sterile process air, reliable springs, seating pressure and leak rates (ie. swing checks that seat tighter and tighter as the reverse pressure builds.... what is the initial leak rate at 2 psi (will this be sufficient to allow for thermal expansion or will this lock in line pressure and allow the line to pressure up). Sealing ratings similar to valve Type IV, type V, type VI shut off etc.
~David F, Project Manager, San Diego, CA
To bleed in BOTH directions at very slow rates in low load low travel speed conditions, whilst creating an instant seal in one direction, and the ability to revert to slow bi-directional bleed once high impact load dissipates.
~Steve B, Engineering Consultant, Barnetby, UK
To be fast acting (highly responsive to water pressures), light enough not to damage the seals in frequent use, avoid "hunting" causing excessive wear and tear.
~Nic T, Research & Development, Johannesburg, South Africa
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Q:
Is there any advice you want to share with users to help them avoid common errors in selection or usage of check valves?
11 answers
Answers:
Orientation of installation. (swing checks). Metal vs. Soft seats - when? Minimum lift flow, Seating pressure, Check valves need maintenance (consider double block and bleed on caustic/acid check such that they can be isolated). Spares - don't use 316L in place of special alloys "in emergency" - buy spares (2) for each application and specify for what application. Chatter, hammer, on large swing checks at low flow (steam). Broken springs, how to confirm working (test ports?? Like a backflow preventer on larger systems).
~David F, Project Manager, San Diego, CA
There is a lot of energy released when these valves slam closed in big high pressure water pipelines. Design your supporting valve chamber to carry these repetitive loads.
~Nic T, Research & Development, Johannesburg, South Africa
Determine the satisfactory application life for the check valve and note, stencil, engrave, or document so that timely replacement occurs before failure.
~Ed C, Engineering Consultant, Houston, TX
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Buying AdviceTop

Q:
Do you have any advice for people relative to buying or using check valves?
10 answers
Answers:
The cheapest valve is not always the best choice. Look at long term usage and maintenance free operation when considering a valve. Look for quality materials used in the construction. Sometimes, it may cost you 1000's times more to replace a cheap defective valve that the extra you pay for a good quality one to start with.
~Rocky S, Design Engineer, Irvine, CA
Revise weight, capacity of sealing, materials resistant to design conditions (P&T), losses through the valve (Cv factor), noise in Db when valve in closing (if it´s supplied in technical information).
~Alfredo Rendueles, Engineering Consultant, Maracaibo, Venezuela
Know pressure, temperature, flow and PSI drop requirements. Know what type of Check Valve is preferred for a specific application.
~John B, Marketing/Sales, Carlsbad, CA
Do your homework, because most of the people selling you the product won't be able to answer your questions down the road.
~Mark C, Marketing/Sales, Farmington, NM
Do your homework, check out manufacturers' claims by following up with installers, operators (users) and maintenance people.
~Nic T, Research & Development, Johannesburg, South Africa
Confirm that the selected check valve is correctly matched to the pressure ratings of the other components in the system.
~Ed C, Engineering Consultant, Houston, TX
Use automated ball valve instead. Don't rely on check valves. Engineer them as only a back up feature.
~David F, Project Manager, San Diego, CA
Always look at resetting ability, and effects of corrosive atmospheres
~Steve B, Engineering Consultant, Barnetby, UK
Select the correct type of check valve for the application
~Bob C, Design Engineer, Sheffield, UK
Pay close attention to cracking pressure
~Tom K, Purchaser, Leitchfield, Grayson


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