Double Block and Bleed Ball Valves are aimed to get a double barrier on the piping, and bleed the fluid trapped between the two balls from a dedicated drain line. Body construction can be either forging or centrifugal casting. Wide range of materials: carbon steels, austenitic or martensitic SS, duplex-superduplex SS, nickel-based alloys.
 Main parts
Part name |
Material |
Body/Bonnet |
A105, LF2, F304, F304L, F316, F316L, F321, F51 |
Ball |
WCB+HCr, A105+HCr/ENP, 2Cr13, 304, 316, 304L, 316L, F51 |
Stem |
2Cr13, 304, 316, 304L, 316L, F51 |
Seat |
PTFE, PPL, Nylon, PEEK, PCTFE |
Valve design can be either Trunnion or Floating type, anti blow-out stem and typically SPE seat design. Drain port is normally provided with a floating ball valve, to be fitted with Final User drain line. Valve seats can be soft or metal to metal hard-faced.
Main reference codes: Standard design in accordance with API 6D / ASME B16.34 / API 6A. Antistatic design as per API 6D and ISO 17292. Valve ends can be flanged (RF, FF, MF or FF, RTJ), according to ASME B16.5 (up to 24”) , Butt-Welding according to ASME B16.25, or Hub, according to customer Requirements. Fire Safe according to BS6755 / API 6FA / API 607, since each sealing point is provided by a secondary fire-safe seal in graphite. Valve soft seats also are provided with secondary metal-to-metal seal in case of fire. Double Block and Bleed ball valves are typically manual operated, but can be equipped also with an actuator (electric, pneumatic, hydraulic).
- Maximum Operating Pressure: Class 2500(6000 psig) @ 100 F degree (38 C degree) - Operating Temperature Range: PEEK Seat : -65 F degree (-54 C degree) to 400 F degree (205 C degree) PCTFE Seat : -22 F degree (-30 C degree) to 356 F degree (180 C DEGREE)
The following optional features are available:
Locking device. Emergency stem seal injection; Emergency seats sealant injection; Weld overlay (316 or Inconel 625) on dynamic sealing areas or in all wetted parts Removable supports; Certified lifting devices; Seal welded fittings.
Main parts
Part name |
Material |
Body/Bonnet |
A105, LF2, F304, F304L, F316, F316L, F321, F51 |
Ball |
WCB+HCr, A105+HCr/ENP, 2Cr13, 304, 316, 304L, 316L, F51 |
Stem |
2Cr13, 304, 316, 304L, 316L, F51 |
Seat |
PTFE, PPL, Nylon, PEEK, PCTFE |
Applications Primary isolation, Sampling, Chemical injection
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