An Introduction To Pressure Relief Valves
Pressure relief valves help by relieving pressure beyond a certain limit. Once standard conditions of operations are met the valve will close once again. While options for this pressure release valves were rather limited in the past, today there are plenty of models to choose from as manufacturers are constantly working to develop specialty and best fit products. It is not uncommon nowadays for safety release valves to be offered in several different options, including the following:
• Metal to Metal Seating – Uses a precision lapping process where pressure relief valves are lapped both by hand and machine. This technique offers the best tightness possible.
• O Ring Seating – Available in Teflon, EDPM, or Viton.
• Stainless Inserts – Use high pressure relief settings which come especially in handy when there is a high risk of corrosiveness. Are available in both a disk-only option as well as with stainless steel trimming and a disk component.
• Back-Pressure Testing – Ensures against reverse leaking. Are tested for leaks at the seating with the standard back-pressure procedure.
When it comes to installation, remember that unless you have received training in this area, you should have a qualified professional hook up your safety release valves. If you are going to do the work yourself, remember that the valve should always be installed in an entirely upright position, being sure to allow for the reseating of the disk valve upon opening. The connecting area should be cleaned properly to remove any grime remaining and a little piping compound should be applied to the inlet side.
Also, when installing pressure relief valves, be certain to always use the proper sized wrench on the hex shaped body. Padded wrenches are usually recommended to tighten to a secure enough setting. When it comes time to test your work, make sure that the lift lever can be opened only when the pressure relief system is at 80 percent of the popping or cracking point. Make sure that the valve is open for a long enough time period to allow for the proper cleansing of the seating area.
When it comes to choosing the best safety release valves for you, it is important not to choose one that is oversized. This can result in the rapid opening or closing of the seating and disk, or even valve chatter. If chattering is an issue for you, it may be in your best interest to actually invest in 2 valves. It is important that you do not exceed 10 percent of your vessels or lines operation pressure. If the valve is venting into the atmosphere, make sure that the outlet is pointed away from any area where people or equipment could be in the way.
These are just a few of the many things you will have to take into consideration when purchasing and installing pressure relief valves. While factory standards have made the process much easier than in the past, it is still recommended that you have a professional help you in the purchasing and installation of these units.