Features of Gate Valves

Standard
Design and Manufacture:
Cast Steel Gate Valve to API 600 (ISO 10434) or API 6D
Cast Stainless Steel Gate Valve to API 603 or API 600,
Forged Steel Gate Valve to API 602.
Inspection and Test: API 598, API600 or API 6D
Flange Dimension: ASME B16.5 (For NPS Below 24), ASME B16.47 Series B, API 605 or ASME B16.47 Series A, MSS SP-44( For NPS Larger than 24)

BW end dimension ; ASME B16.25

Socket Weld Dimension: ASME B16.11

Face to face and end to end: ASME B16.10

 Pressure Temperature Ratings: ASME B16.34

Design of Disc

Gate Valves with NPS  ≥ 2" are of flexible wedge.

Gate Valves with NPS  ≤ 2" are of solid  wedge.

The type of Cover Washer

Carbon Steel or stainless Steel +Flexible graphite combined gasket is used for class  150 Gate Valve,

Stainless Steel + Flexible Graphite wounded gasket is used for class 300 Gate Valve

Stainless Stell + Flexible graphite wounded gased is used for Class 600 Gate vale,

Ring joint gasket is also optional for class 600 Gate Valve.

Ring Joint gasket is used for class 900 gate valve.

Pressurized seal design is used for class 1500--class 2500Lb gate valve.

Actuation

Hand wheel or gear box is usually used for gate valv actuation,

Chain Wheel and electric actuator can be also used for gate valve actuation if being requested by the customers.

Packing Seal

Molded flexible graphite is used for packing material. PTFE or combined packing material can be also used if being requested by the customer.

The internal surface of the stuffing box, of which area is contacted with the packing, is of excellent finish. The stem surface, contacting with the packing,s hould be rolled and pressed after being precisely machined, so as to reach to the high finish and compactness and ensure the reliable tightness of the stem area.

Back sealing Design

All our gate valves have the back sealing design. In most cases, the carbon steel gate valve is fitted with a renewable back sealing. For stainless steel gate valve, the back seat is machined directly n the bonnet or is machined after welding. When the gate valve is at fully open position, the sealing of the back sealing can be very reliable. However, as per the requirement of API 600, it is not advisable to add or change packing by the means of back sealing when the valve is pressure containing.

Seat

For carbon steel gate valve, the seat is usually forged steel. The sealing surface of the seat is spray welded with hard alloy specified by the customer. Renewable threaded seat is used for NPS ≤ 10" GATE VALVE, and welded on seat can be also optional if being requested by the customer. Welded on seat is used for NPS ≤ 12" Carbon steel gate valves. For stainless stell gate alve, integral seat is usually adopted, or to weld hard alloy directly integrally. Threaded or welded on seat is also optional for stainless steel gate valve if being requested by the customer

Stem Design.

The stem is of integral forged design. The minimum diameter of the stem shall per the standard requirement. The connection of the stem and disc is T Type. The strength of the connecting area is bigger than that of the T Threaded part of the stem. The strength test of that area conforms to API 591.

Special Gate Valve

Besides the general gate valves, Goole also makes cryogenic gate valve, jacketed gate valve, bellow sealed gate valve, extension stem gate valve for underground application, flat gate valve, etc.