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Pneumatic Safety Valves

Frequently Asked Questions

  1. How do I locate a local distributor for a special item?
  2. How do I obtain flow capacities for ASME safety valves?
  3. What is the difference between a safety valve and a relief valve?

1. How do I locate a local distributor for a special item?

Please contact us and we will put you in touch with a distributor in your area.

2. How do I obtain flow capacities for ASME safety valves?

The flow capacity charts for all of our safety valves are shown under the Products, ASME Safety Valve section of our web page.

3. What is the difference between a safety valve and a relief valve?

Control Devices offers two standard types of pressure relief devices for air.

A safety relief valve, or pop-off valve, is set to a predetermined pressure using a spring force to counteract the air pressure force. When the force created from the air pressure becomes greater than the spring force, the valve ‘pops’ fully open and vents air to the atmosphere. Safety relief valves are sized in such a manner that the valve will always have a greater flow capacity than the source creating the air pressure (i.e. an air compressor). The valve will remain open until a reseat pressure is reached. This reseat pressure varies with valve type and is usually between 35% to 75% of the set pressure. Control Devices has eight series of valves that are manufactured in accordance with Section VIII of the ASME Boiler and Pressure Vessel Code. We also manufacture a wide range of non-code valves. See our Products section for information on the valve types.

A relief valve is set to a predetermined pressure with a spring force counteracting the force created by the pressure from the air. When the force created from the pressure of the air becomes greater than the force of the spring, the valve will start to open and flow to atmosphere. As the pressure continues to increase, the valve will open further, allowing more flow. As the pressure decreases, the valve will close near the pressure at which it opened.

90 Day Limited Warranty

Control Devices, LLC warrants that every new product, when used for its normal and intended commercial or industrial purposes, and when properly installed, not modified in any unauthorized manner, and properly serviced, will be free from defects of material and workmanship for a period of 90-days (the “Warranty Period”) from the date of first purchase from Control Devices, LLC. During this Warranty Period, Control Devices, LLC will, at its option, repair, replace or refund the purchase price of its product which fails to conform to this limited warranty under normal use and service.

In order to be eligible to have product repaired or replaced or the purchase price refunded, the product and all supporting documentation requested by Control Devices, LLC must be submitted to Control Devices, LLC at 1555 Larkin Williams Road, Fenton, MO 63026, at customer’s costs, during the Warranty Period. No claims will be allowed for labor, transport or other costs. This limited warranty extends only to persons or organizations that purchase product directly from Control Devices, LLC for the purpose of resale.

This limited warranty is voided by product modification, misuse, damage (including, but not limited to, by accident, fire or chemical corrosion), or use in a manner not recommended by Control Devices, LLC.

THE REMEDIES DETAILED ABOVE ARE THE SOLE AND EXCLUSIVE REMEDIES FOR A BREACH OF THE LIMITED WARRANY DESCRIBED HEREIN.  THIS LIMITED WARRANTY IS MADE IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. CONTROL DEVICES, LLC EXPRESSLY DISCLAIMS ALL IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. TO THE EXTENT PERMITTED BY LAW, CONTROL DEVICES, LLC DISCLAIMS LIABILITY FOR ANY AND ALL CONSEQUENTIAL AND INCIDENTAL DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THE ABOVE LIMITATIONS OR EXCLUSIONS MAY NOT APPLY TO YOU.

This Limited Warranty gives you specific legal rights, and you may also have other rights which may vary by state. This is the only express warranty made by Control Devices, LLC. No Control Devices, LLC employee, retailer, or dealer has the authority to make any warranty, representation, promise or agreement on behalf of Control Devices, LLC, except as expressly written in this limited warranty.