Chemical Resistant Relief Valves

A relief valve serves to bleed liquid from a system to reduce or prevent high pressure conditions.  These conditions are usually  caused by pumps or sometimes thermal expansion of a liquid.  In almost all cases, the liquid by-passed through the valve and directed to a lower pressure area such as the original supply tank.  Relief valves are not effective to prevent water hammer or solution pulsation. 

 Operation - Once the relief valve is set, the valve will remain closed as long as the tank or line pressure does not reach the set pressure.  The valve will begin to weep or relieve solution when the set pressure is reached and will require an overpressure of approximately 40% to fully open.   When the pressure falls below the set pressure, the valve will again close.

We recommend that the following information be considered with sizing a relief valve.  Inlet pressure, set pressure, maximum flow and limit of pressure increase during high flow rate conditions.  We can be of service in selection of a valve to assure compliance with your requirements.

Other uses may include; anti-siphon valves, by-pass valves, and back pressure valves.

The following valves all are designed with the system pressure force working across the valve seat against a spring.  As a general rule, the larger the surface, the more accurate and responsive the valve will be to the desired set pressure.  Sealing between the solution from the spring area is best by using a diaphragm type seal.

RVD Series Angle Pattern Relief Valves - Diaphragm Type Seal

• PVC - CPVC - PVDF - Teflon®
• 1/4" to 1/2" FNPT
• Pressure Settings 5 to 150 PSI
• Viton®, Teflon® or Buna-N® Diaphragm Seal

An elastomer diaphragm is backed up with a plunger to provide pressure relief with out and metal contact with the product being pumped.

RVDM Series Inline Pattern Relief Valve  - Diaphragm Type Seal

• PVC - CPVC - PVDF - polypropylene
• 1/2", 3/4" or 1" FNPT
• Pressure Settings 5 to 100 PSI
• Viton® or EPDM Diaphragm Seal

The use a rolling diaphragm as a primary seal with a secondary flat diaphragm provide excellent service life even when using caustics and other solutions that form salts or abrasives.

RVDT Series Inline Pattern Relief Valve  - Diaphragm Type Seal

• PVC - PVDF - polypropylene - Teflon®
• 1/4", 1/2", 3/4" or 1" FNPT
• New - Now available 1 1/2" and 2"
• Pressure Settings 5 to 100 PSI
• Large Surface Teflon Diaphragm Seal
• Large Sensing Surface For Accuracy
• Use As By-Pass or Back Pressure Valve

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A large Teflon® diaphragm sensing area provides excellent sensitivity and excellent chemical resistance over a wide range of applications.

RVTX 300 Series 3" Angle Pattern Relief Valve  - Diaphragm Type Seal

• PVC body with Viton®, EPDM or Buna diaphragm
• New 3" FNPT
• Pressure Settings 5 to 100 PSI
• Large Sensing Surface For Accuracy
• Use As By-Pass or Back Pressure Valve

A large rolling diaphragm sensing area provides excellent sensitivity and excellent chemical resistance over a wide range of applications.

RVT Series Angle Pattern Relief Valves

• PVC - CPVC - PVDF - Teflon
• 1/2" to 2" FNPT
• New - Now available 3" PVC
• Pressure Settings 5 to 100 PSI
• Teflon® shaft - Viton® 'U' Cup Seals

This valve has provided excellent service for thousands of customers for many years.   These valves can be factory or field set to open when over pressure conditions are present and bypass liquid to a relief location.  The vent port give early warning against seal failure.

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