PROSERV 25412 RK VER 014 3/4″ Shuttle Valve Repair Kit

PROSERV 25412 RK VER 014 Shuttle Valve Repair Kit (3/4-Inch) for NOV-Shaffer BOP Systems

The PROSERV 25412 RK VER 014 is an original equipment manufacturer (OEM) grade, heavy-duty soft-goods overhaul kit engineered specifically for 3/4-inch subsea and surface blowout preventer (BOP) hydraulic shuttle valves. Operating in dual-redundant hydraulic circuits, 3/4-inch shuttle valves isolate primary and secondary hydraulic supply lines to execute fail-safe actuation of shear rams, pipe rams, annular preventers, and hydraulic riser disconnect systems.

Manufactured to meet stringent API Spec 16D and API 6A / 17D standards, this internal overhaul kit contains high-integrity fluid seals, elastomeric O-rings, energized back-up rings, wiper rings, and internal seat seals formulated from hydrogenated nitrile butadiene rubber (HNBR), high-durometer Viton (FKM), and virgin/filled PTFE. The kit restores zero-leakage internal sealing, eliminates hydraulic cross-talk between pilot lines, and guarantees rapid shuttle transit under differential pressures up to 5,000 PSI (345 bar).

Model Details

• Manufacturer / OEM: Proserv Fluid Technology / Gilmore Controls
• Model Designation: Shuttle Valve Overhaul Kit (3/4″ Nominal Bore)
• Manufacturer Part Number (MPN): 25412 RK
• Version / Revision Level: VER 014 / REV N / REV J
• Target Valve Series: 3/4″ High-Pressure Hydraulic Shuttle Valve Series (Shaffer / Cameron / Proserv / Gilmore configurations)

Technical Specifications

Key Features

1. High-Differential Fluid Isolation: Engineered to maintain absolute seal boundary integrity between redundant pilot hydraulic banks without fluid intermix or bypass blow-by during active valve shifts.
2. Rapid-Response Shuttle Seal Geometry: Low-friction, dual-lip energized profile minimizes dynamic breakaway torque, ensuring instantaneous shuttle transit times (< 45 ms) under sudden hydraulic command.
3. Extrusion-Resistant Multi-Layer Back-ups: Virgin PTFE and PEEK anti-extrusion rings prevent elastomer nibbling and degradation under aggressive cyclic pulse loads up to 5,000 PSI.
4. Broad Offshore Fluid Compatibility: Fully chemically resistant to modern water-glycol subsea hydraulic fluids, high-pH completion brines, and harsh synthetic oil-base control line media.
5. Complete Overhaul Bill of Materials: Pre-packaged matched set contains all critical dynamic seals, static O-rings, and retaining elements required for full field rebuild of one complete 3/4″ shuttle valve assembly.

Applications

• Subsea & Surface BOP Control Pods: Shuttle logic manifold circuits for subsea multiplex (MUX) and direct hydraulic control systems (NOV Shaffer, Cameron, Hydril).
• Emergency Disconnect Packages (EDP) & Lower Marine Riser Packages (LMRP): Auto-select shuttle circuits governing shear ram boosters and acoustic secondary control lines.
• Accumulator / Koomey Control Units: Primary/secondary bank selector circuits within surface BOP hydraulic power units (HPUs).
• Subsea Wellhead Tree Controls: Workover control systems (IWOCS) requiring high-cycle hydraulic switching redundancy.

Engineer’s Rebuild Checklist: 3/4″ Shuttle Valve Overhaul

• Pre-Disassembly Wash & Decontamination: Clean the valve exterior thoroughly with an approved solvent before cracking the end caps. Prevent any sand, barite drilling mud, or pipe scale from entering the shuttle cavity.
• Bore Inspection & Lapping: Inspect the inner shuttle sleeve bore using a 10x bore-scope. If axial scratching, pitting, or wire-drawing is detected, replacement of the sleeve or full valve body is required. Never install a fresh 25412 RK kit into a scored valve body.
• Elastomer Lubrication: Pre-lube all dynamic O-rings and backup rings with a thin, uniform film of fluorinated subsea grease (e.g., Krytox GPL 205 or manufacturer-specified water-glycol compatible assembly lubricant). Never assemble dry.
• Anti-Extrusion Ring Orientation: Ensure concave/split backup rings face opposite to the high-pressure vector as delineated in the assembly diagram. An inverted backup ring will pinch and fail during initial pilot pressurization.
• Torque Specifications: Torque end caps uniformly in cross-patterns to OEM specified values (typically 85–95 ft-lbs for 3/4″ 5K carbon steel/stainless housings). Over-torquing will warp the internal seal retention shoulders.
• Hydrostatic Proof & Differential Shift Testing:

• • Apply 300 PSI pilot pressure to Port A; verify zero leakage at Port B and full flow to the outlet.
  • Reverse pressure to Port B; verify instantaneous shuttle transit and zero leakage at Port A.
  • Lock in 5,000 PSI hydrostatic test for a minimum holding period of 15 minutes per API 16D requirements (permissible drop: 0 PSI).

Frequently Asked Questions

What symptoms indicate a failed 3/4″ shuttle valve seal kit on a BOP stack?

The most common indicators are cross-line pressure equalization (pressure bleeding from an active pilot line into an idle secondary line), delayed or sluggish ram closing response times, and noticeable fluid loss or pressure drops on the hydraulic accumulator (Koomey) unit without active function execution.

Is the PROSERV 25412 RK VER 014 kit compatible with synthetic water-glycol fluids?

Yes. The seals and dynamic backup rings in the 25412 RK VER 014 kit are specifically formulated for full chemical resistance against modern subsea BOP water-glycol hydraulic fluids (such as Castrol Brayco, Erifon, and Stack-Magic) without swelling, hardening, or losing tensile recovery across wide temperature ranges.

How does this repair kit differ between REV J, REV N, and VER 014?

Revision levels designate updated elastomer formulations and optimized anti-extrusion ring dimensional tolerances introduced to withstand aggressive micro-pulsing in modern high-flow subsea MUX control systems. The VER 014 provides backward-compatible performance across all previous revision housings.

What is the recommended field service interval for this kit?

Under standard API 53 and API 16D guidelines, subsea BOP control valves should receive a complete soft-goods overhaul every 3 to 5 years during between-well maintenance (BWM) intervals, or immediately following any significant fluid contamination event or failed periodic pressure test.