Relief and safety Valves are used in high pressure systems to control the pressure and keep balance of the system. The different between safety valves and relief valves is that the safety valves fully open or close under a certain pressure while the relief valves can open in proportion to the pressure in front of them. The safety and pressure relief valves are used automatically. They both operate under similar conditions. When the pressure builds up in a system, it has to be managed by releasing the material to flow through. These valves have a threshold pressure at which they open. The consolidated safety and safety relief valves comprise of a bonnet vent and bellow with springs.
Stainless Steel Safety Valve
316 Boiler Pressure Relief Valves
ASTM A351 CF8 Temperature Safety Valve
The springs are set up for the threshold pressure and when the pressure exceeds the threshold, the spring is pushed into the bonnet vent and the bellow opens the valve. The Safety Relief Valves can be open and shut valves. They either open or shut off at any given pressure. This is mostly for the safety of an application not to explode under high pressure. The Pressure Relief Valve on the other hand releases the material after the threshold pressure, but not fully. If the pressure is slightly higher the threshold, then the valve opens slightly. If the pressure is very high above the threshold, it opens wider. It also functions in the same manner when the pressure drops down. The valve closes in proportion to the pressure. The safety valve shuts down at once only when the pressure is below the threshold.
Size | 50NB — 600NB |
---|---|
Pressure | 150PS1 |
Temperature | 0 Deg C - 1200 Deg C. |
Body , Chest | Solid One piece casting of Cast Iron Fg 260, Cast Steel Gr WCB ,CF8,CF8M. |
Seat | Integral to Body, Soft, Optional. |
Gate | AISI SS 304,316,316L,317,317L |
Screw Spindle | AISI SS 410,304,316. |
Nut | Brass |
Yoke | Plate type of MS . |
Gland Follower | Cast Iron , Cast steel , Ductile Iron ,CF8,CF8M. |
Hand Wheel | Cast Iron , Cast steel , Ductile Iron |
Gland Packing | PTFE , PTFE Impregnated |
Ends | Lugged |
Port | STANDARD [Round], Optional V Port, Diamond Port,. |
Set Pressure Ranges | 20 to 2,000 psig (1.38 to 137.9 barg) |
Temperature Range | -450 to 550°F (-268 to 288°C) |
Minimum Ambient Temperature | -20° °F |
Maximum Ambient Temperature | 200° °F |
Minimum Operating Temperature | -40° °F |
Maximum Operating Temperature | 300 °F |
A351 CF8 consolidated safety and safety relief valves
Stainless Steel 304 Boiler Safety Valve
ASTM A351 CF8M Spring Loaded Safety Valve
Stainless Steel Air Compressor Pressure Relief Valve
Cast Steel Temperature Safety Valve
Brass Relief and safety Valves
Pressure Relief Setting | 10.3 to 27.6 barg 150 to 400 psig |
Maximum Operating Pressure | 27.6 barg 400 psig |
Air Flow Rate | 130 to 1776 SCFM |
Relief Valves are designed to control pressure in a system While Safety Valves are used for controlling the pressure in a system they release pressure immediately in the event of an emergency or system failure
The Setpoint of relief valve is usually set at 10 Percent above working pressure limit while safety valve is usually set at 3% above working pressure limit.