Grove Cameron’s B4, B5 & B7 Side-entry Ball Valves and Measurement business segment is a leading provider of valves and measurement systems to the oil and gas industry.
We provide large-diameter valves for use in natural gas, LNG, crude oil and refined products transmission lines as well as in many other general industrial applications.
Rigorously tested, field-proven and backed by our CAMSERV™ aftermarket services, Cameron’s GROVE® valves are among the best known valves in the world.
GROVE B4 Side-entry Ball Valves Application
GROVE split-body side-entry ball valves are manufactured in a wide range of diameters and
pressure classes. In the standard versions, the valves are specified for transmission pipelines, pumping, compression and reinjection units, offshore platforms, onshore terminals, pig traps, measuring stations and surge-relief skids.
In the special versions, the valves are used for subsea installations and in LNG plants. Split-body construction allows the use of forged materials in various grades of carbon steel, stainless steel and high alloys, thus complying with the most severe service conditions.
Standard Features
The standard design valve code is B4.D.
• Double-barrier stem seals (the upper seal can be replaced with the valves in-line, under pressure, with the ball in the closed position)
• Short coupled trunnions reduce unit bearing loads and operating torque
• Factory-positioned external stops
• Stem separated from the ball; anti-blowout design; side load on stem
• Plastic polymer insert for seat sealing
• Self-relieving seats for ASME Classes 150 and 300
• Metal-backed, self-lubricating PTFE sleeve bearing and thrust washers reduce torque and extend service life
• Nickel plating for trim parts
• Fire-safe graphite rings for protection against external leakage
Features Upon Request
According to the design impact of the optional features, the valve code may change to B4.B, B4.C, etc.
B4 – ALL TYPES
• PTFE various grades of reinforced gaskets, spring energized, for stem and seat sealing
• Antistatic device
• Metal-to-metal seats
• Double-sealing barrier in both directions (DPE) for ASME Classes 600, 900 and 1500; body relief valve for overpressure due to liquid thermal expansion
• Double block-and-bleed
• Explosive decompression-resistant seals
B4.B TYPE
When the valve design includes one or more of the following variations with respect to the standard design, the denomination becomes B4.B.
• Triple-barrier stem seals; upper stem seal O-ring replaceable with pressure in-line with the ball in the closed position
• Self-relieving seats
B4.C TYPE
This version of the B4 valves (in ASME Classes 600, 900 and 1500) features :
• O-ring seat seal
• Double-sealing barrier in both directions (DPE) and body pressure relief valve
Body Construction
The body is made of three forged parts, and the bolted construction allows disassembly on the job site for repairs.
The body drain is located in the lowest part of the body cavity and consists of a 1/4″ NPT drain valve with safety plug. Graphite rings are provided to guarantee full compliance with API 6FA and BS 6755 Part 2 fire-safe standards.
Stem Construction
The stem function is to transmit torque and to absorb the line pressure thrust together with the trunnion. The stem of the GROVE B4 valves has an anti-blowout design and incorporates a double-barrier system. The pressure thrust on the stem is supported by a thrust washer in antifriction material.
Seat Seal
The soft sealing between the seat and the ball is achieved by a plastic insert on B4.B, B4.D valves and by an O-ring on B4.C valves.
The block-and-bleed and double block-and-bleed requirements are available as per API 6D definition on all types of B4 valves.
Self-relieving seats are standard on all B4.B, B4.C and B4.D ASME Classes 150 and 300.
Independent sealing on upstream and downstream seats is available on B4.C and B4.D ASME Classes 600, 900 and 1500.
Ball Position
For valves normally mounted with lever, the ball open and closed positions are ensured by corresponding stops on the bearing housing. The lever position parallel to the line flow means the valve is open. For valves with gear or actuators, the stops are set at the factory
as primary stops. An “open/ closed” indicator also is provided
MATERIALS SPECIFICATIONS
Materials Selection
The quality of the valve design also depends on the material selection.
After examination of service conditions, the selection criteria are based on the verification of the physical and chemical characteristics of the materials or product.
For the soft sealing (O-rings, inserts and lip seal gaskets), the guidelines to be followed are relevant for hardness, tensile strength, modulus, compression set, swelling and fluid suitability.
The process is qualified so that the final thickness after machining can guarantee the chemical composition as per the relevant ASTM standard. The final check is carried out
by the liquid penetrant method.
Weld Overlays
Sealing areas and other critical parts of the valve can be weld overlayed in case of corrosive service.
More frequently used materials are AISI 316L and Alloy 625.
Duplex Stainless Steels Metallurgy
On duplex (22 Cr to 2 Ni) and superduplex (25 Cr to 5 Ni) stainless steels, corrosion-resistance qualification check can be as follows :
• Chloride corrosion as per ASTM G48 (104° F or 40° C, 72 hours)
• Cracking as per ASTM G36 (302° F or 150° C, 500 hours)
• Pitting corrosion PRE = 33 min. for duplex, 40 min. for superduplex
• Ferrite content 40% to 60%, as per ASTM E562
Nace Requirements
On request, GROVE side-entry ball valves can be supplied in accordance with NACE MR0175.
Severe Wet Sour Gas Service
In addition to NACE MR0175, the additional qualifications can be :
• Sulfur ≤ 0.015%
• Hydrogen-induced cracking as per NACE TM-02-84 (96 hours)
• Sulfide stress corrosion cracking as per NACE TM-01-77 (720 hours)
Source: camerongroveestate.com
