Trunnion Mounted Side Entry
Trunnion Side Entry Ball Valves typical application is for gas or crude oil pipelines, larger sizes (up to 60 inches) and higher pressure classes (ASME 4500 or API 15000psi). Body construction can be two or three pieces for smaller sizes (up to 6” RB), three pieces for larges dimensions. Raw material can be either forgings or centrifugal castings. Wide range of materials: carbon steels, austenitic or martensitic SS, duplex-superduplex SS, nickel-based alloys. Bolted body as a standard, welded body for special applications (see specific section).
Valve main technical features include anti blow-out stem and valve seats design available in three different versions:
- SPE (Single Piston Effect): the seat is energized by upstream pressure only .
- DPE (Double Piston Effect): the seat can be energized by upstream pressure or by body cavity pressure .
- DUAL (SPE upstream and DPE downstream): combining the two seat designs explained above, a double barrier can be assured in case of seat sealing failure.
Main reference codes:
• Standard design can be in accordance with API 6D / API 6D SS / 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”) or ASME B16.47 (26” and above), 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.
Trunnion ball valves can be manual operated (lever or gearbox depending on valve size), but also equipped with an actuator (electric, pneumatic, hydraulic, gas-over-oil etc.).
Standard design is soft seated and gear operated, the following special designs are also available:
- CRYOGENIC (see specific section): full austenitic stainless steel valve, provided with PCTFE or metal seat, lipseals as static and dynamic seals, stem extension according to BS6364 (or as per customer requests).
- METAL-TO-METAL SEAT: for high temperatures (larger than 250°C) or dirt/slurry service, hard facing on seat and ball contact surfaces (Tungsten or Chromium Carbide).
- SUBSEA DESIGN: for subsea applications, Side entry Ball valves are provided with additional seals, blind nuts, subsea actuators etc. Valve design according to API 6D SS and ISO 14723.
- STEM EXTENSION. For special applications the operator (lever/gear/actuator) can be lifted by an extension fixed to valve body, and a joint coupled to the stem.
The following optional features are also available:
- Locking device.
- Floating ball valves for drain and vent connections (if prescribed by Customer requirements).
- 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.
- Welded glandplate.
- Seal welded fittings.
