Gosco S-Class Block & Bleed Valves

Gosco S-Class Block & Bleed Valves

Gosco S-Class Block & Bleed Valves combine all the unique features in a standard S-Class valve with encapsulated seats that are not only live loaded, but also truly bi-directional. 
This makes the Gosco a true Double Isolation and Bleed valve. With the best shaft sealing system in the world, any exotic alloy option and high pressure capabilities (up to Class 4500), these valves are versatile enough to tackle the toughest applications.


Gosco S-Class Block & Bleed valves are essentially two bi-directional valves with a bleed valve between them. We offer two options: two valves with a spacer/bleed valve between them, 
or an integral body with two internal valves and a bleed valve. Both options meet all definitions of API 6D for double block & bleed (DBB) and double isolation & bleed (DIB), 
as well as OSHA double block & bleed (DBB).

Shaft Sealing

The core of our patented shaft sealing system is the dual live-loaded packing. To eliminate side loading on the packing, we’ve added two shaft guides to support the shaft at the bottom and the top. For a third layer of protection, a fugitive emissions port can be drilled to monitor the areas between the packing sets. Our shaft sealing system has been tested by TUV, and exceeds all current and projected fugitive emission standards.

Bi-Directional Sealing

To meet all definitions of Gosco S-Class block & bleed valves (BB, DBB, DIB and OSHA DBB), the block valves MUST have bi-directional sealing at full design pressures, and at a 1psi differential. S-Class block & bleed valves use live-loaded encapsulated seats to accomplish this. That means we can offer you any type of block & bleed valve. The difficulty is finding out what type you really need.

Encapsulated “Soft” Seats

S-Class encapsulated soft seats are used for high cycle, abrasive, and high pressure/temperature applications. Our proprietary live-loaded design allows us to completely encapsulate the insert on all four sides, leaving only a small section of the “Soft” material exposed for sealing. The insert is held in place with “barbs” that prevent it from extruding out of the carrier. A special fixture compresses the seat assembly to 3 times the max pressure rating of the valve, so that the insert takes a compression set. The seat profile is then machined in to the insert, and it is match lapped to the ball. For abrasive applications, it can be used in conjunction with a boronized, arcuate cut ball.

Exotic Alloys

Cast, forged or bar stock, Gosco manufactures ball valves out of any metal – even specialty metals that require vacuum casting (like titanium). We are not restricted to making just the body from exotic alloys – we can manufacture any component to suit your needs, right down to the bolting. Our engineering team at Gosco Valves has extensive experience in corrosive applications, and can recommend the appropriate material to use for specific media.

Extended Bonnet

The extended bonnet is perfect for insulated lines as there is at least 2″ between the top of the flange and the bottom of the Clearview mounting pad. This allows you to fully insulate the valve and still have access to make packing adjustments, without having to remove the actuator or insulation. The valve shaft flats are also visible, and the actuator is raised away from the elevated process temperatures, preventing damage to the actuator seals.

Gosco S-Class with Clearview Mounting Pad

The Clearview mounting pad is a combination of an ISO 5211 mounting pad for easy installation of valve accessories, and a CNC machined/cast bracket that guarantees accurate actuator alignment. Packing adjustments can be performed in-line without removing the actuator, and the double “D” shaft gives you a visible indication of the position of the valve. Clearview also raises the actuator away from the valve, and acts as a heat sink to protect it from high temperatures.

  • Gosco S-Class Block & Bleed Sizes

    NPS ½ FP to NPS 16 SP
    ½″ FP to 16″ SP

  • Block & Bleed Connections

    150# to 4500#, NPT, SW,
    BW, Graylock and Custom

  • Block & Bleed Applications

    Customizable with a bubble tight seal, exotic alloys, & custom ends

  • Block & Bleed Temperatures

    -50°C to 260°C 
    -58°F to 500°F

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Gosco S-Class Block & Bleed Valve

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Gosco S-Class Valve Catalogue

Size: 7 MB

Gosco S-Class Valve Presentations

Size: 9 MB

Gosco S-Class Valve IOM Manual

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