Relief Systems of the OmniSeal® Double Block & Bleed Expanding Plug Valve

OMNIVALVE

OmniSeal® Double Block & Bleed Expanding Plug Valve

High integrity double block and bleed expanding plug valves for product isolation, blending, metering, custody transfer, terminal, storage and other land or offshore zero-leakage applications.

RELIEF SYSTEMS (check image below)

• MANUAL BLEED WITH THERMAL RELIEF TO UPSTREAM
• MANUAL BLEED WITH THERMAL RELIEF TO UPSTREAM - WITH GAUGE
• THERMAL RELIEF TO ATMOSPHERE
• MANUAL RELIEF TO ATMOSPHERE, THERMAL RELIEF FROM DOWNSTREAM AND BODY TO UPSTREAM
• MANUAL BLEED TO ATMOSPHERE;

The OmniSeal® DBB expanding plug valve can be delivered with a variety of relief systems. Some of the more common relief systems are:

• STANDARD : MANUAL BLEED WITH THERMAL RELIEF TO UPSTREAM

This is the standard relief systems offered on the OmniSeal® DBB valve.  It is designed to relieve excess pressure in the valve cavity due to thermal expansion when the valve is in the closed position. It is similar to a thermal relief to atmosphere system; however, it has a manual valve that provides both manual and automatic relief capabilities. The thermal relief system will relieve pressure to the upstream if differential pressure exceeds 25 psi.

IMPORTANT: In order for the automatic relief system to function properly, the valve that controls the upstream relief must be kept open and the valve that controls the manual bleed to atmosphere must be kept closed.

 

• MANUAL BLEED WITH THERMAL RELIEF TO UPSTREAM - WITH GAUGE

This relief system is designed to relieve excess pressure in the valve cavity due to thermal expansion. It is similar to a thermal relief to upstream system; however, it uses a gauge to measure the valve seal integrity. Using this system a positive seal can be verified at all times without dispersing any line media. The thermal relief system will relieve to upstream when differential pressure exceeds 25 psi.

 

• THERMAL RELIEF TO ATMOSPHERE

This system is designed to relieve excess pressure in the valve cavity due to thermal expansion when the valve is in the closed position. This is an automatic system that relieves when trapped internal body pressure reaches the working pressure of the valve. The excess pressures will relieve to atmosphere or to a receptacle the customer has piped to the bleed port.

 

• MANUAL RELIEF TO ATMOSPHERE, THERMAL RELIEF FROM DOWNSTREAM AND BODY TO UPSTREAM

This system is designed to relieve excess pressure in the valve cavity and downstream components due to thermal expansion when the valve is in the closed position. This system operates in the same manner as the standard relief system; however it also has a thermal relief from downstream to upstream. The thermal relief system will relieve to upstream if differential pressure exceeds 25 psi. The upstream and downstream relief systems operate independently.

IMPORTANT: In order for the automatic relief system to function properly, the valves that control the upstream and downstream relief must be kept open and the valve that controls the manual bleed to atmosphere must be kept closed.

 

• MANUAL BLEED TO ATMOSPHERE

This system is operated manually. When the valve is in the closed position, the manual bleed valve can be opened to confirm seal integrity. The manual bleed valve should be closed before opening the valve bore.

 

• CUSTOMER-SPECIFIED RELIEF SYSTEMS

The OmniSeal® DBB valve is also available with welded or other customized relief systems.  Please contact us for more details.

Visit our other pages: OMNIVALVE / OMNISEAL product page and OmniSeal® Double Block & Bleed Expanding Plug Valve overview.