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Piping Class DBB Valves

Double Block & Bleed Valves

Dublok double block and bleed valve assemblies have three valves – primary isolation, secondary isolation and bleed – all integrated into a single block.  If required the inlet or outlet end connection can incorporate a spring loaded in-line piston check valve.  The end connectors are interchangeable and can be specified to suit exact requirements.

Our Ball valve double block and bleed assembly is very compact and is recommended for general services.  The valve can incorporate Needle, Globe, Gate and Check valves into the design to suit particular duty specifications as required.


For sampling points the valve can be supplied with a probe attached by means of a full penetration butt weld

Quill steadies can be fitted if required



Chemical Injection Valves

Single block and check assemblies have proved to be very successful because of the many advantages over conventional injection point arrangements.  Traditionally these points have been assembled from conventional valves and flanges with considerable penalties in terms of weight, space and leak paths.

This configuration is a very robust and compact unit.  It may or may not be fitted with a probe and can be supplied in single block and check, double block and check or double block and bleed and check configurations.

The injection probe is attached by means of a full penetration butt weld to an extension of the valve body forging, thereby eliminating the separate flange usually used to carry the probe.




Single Block with Needle or Globe Valves 

Single Ball or Gate valves can be followed by a Needle or Globe valve for sampling or blowdown.  The Ball or Gate valve provides primary isolation and the Globe or Needle valve provides flow control.  For sampling points the unit may be fitted with an integral welded-on probe.  The probe is attached by means of a full-penetration butt weld onto an extension of the valve body, thereby eliminating the separate flange usually used to carry the probe.




Double Block Valves

Typical double block assemblies have two valves integrated into a single body thus eliminating the flanges usually involved.  The end connections are interchangeable and can be specified to suit exact requirements, thereby eliminating unnecessary flanges, reducers and fittings.

Double block units can be provided in any combination of ball, gate, needle or globe valves.




Gate/Ball Valves

This four valve unit is an excellent example of the  versatility of the Dublok design.  It has a mixture of gate, ball and check valves all incorporated into a neat compact assembly.




Hybrid Valves

Frequently, an oversized valve will be used purely for the strength of the connection to the main line.  Clearly this is wasteful in terms of space, weight and cost.  The solution is to use a Dublok hybrid valve, with dissimilar ends.  The one piece forged reducing inlet has a heavy wall to provide the required strength.  The valve itself is the same size as the outlet so it is no longer, heavier or more expensive than need be.

Dramatic space and weight savings are possible using this valve.



Piping Class DBB Valves

DBB Ball valve with Ball Valve Bleed and Hub End Connections


Piping Class DBB Valve 2

DBB Ball Valve with Needle Bleed c/w reducing flange End Connections


Dublok PC 4

DBB Ball Valve with Needle Bleed c/w extended Handles and extended Vent for insulated pipework


Piping Class DBB Valve 4a

DBB Valve with Globe Primary and Ball Secondary


Dublok PC 6

DBB Gate Valve with Needle Bleed


Dublok PC 7

Hybrid DBB Valve with Gate Primary, Ball Secondary and Needle Bleed


Piping Class DBB Valve

DBB Chemical Injection Valve with Hub End Connection


Piping Class DBB Valve 8

4 Way Ball Valve


Piping Class DBB Valve 9

DBB Valve Reduced Bore with Needle Valve Bleed