API Pressure Sealing Globe Valve

Product Details: Pressure Seal Globe Valve
Pressure Seal Globe Valve -> Pressure Seal Globe Valve
Pressure seal bonnet is suggested for better closure in high pressure condition, while bolted bonnet is still available for customer's option.

The pressure seal design incorporates a metal-to-metal seal that becomes tighter as the pressure increases. The initial preload deforms the taper on the soft iron gasket to mate with the taper on the bonnet. The thin knife-edge on the gasket is wedged tightly between the body and the bonnet. The shallow angle insures that the gasket is sealed tightly with only a small upward force on the bonnet. Once the initial seal is created, the body/bonnet joint will remain leak free regardless of thermal or pressure conditions in the valve. After the joint has been assembled, there is no further need to adjust bonnet cap screws.

Applicable Standards of Pressure Seal Globe Valves:
A) Design&Manufacture: BS 1873, ASME B16.34
B) Face to Face: ASME B16.10, EN 558, BS2080
C) Connection End: ASME B16.5, ASME B16.25, EN 1092
D) Test and Inspection: API 598, EN 12266, BS 6755

Sizes: 1/2" - 12" or DN12 - DN300
Pressure Rating: Class150 - Class2500 or PN16 - PN420
Materials of Valve Body: WCB, LCB, WC6, WC9, C12, C5, CF8, CF3, CF3M, CF8M, etc.
Operated by: Handwheel, Gear, Pneumatic, hydraulic and Electric actuator.

The features of globe valve
Bolted Bonnet; Outside Screw and Yoke; Rising stems; Metallic seating surfaces.

Body and Bonnet Connection
The body and bonnet of Class150~Class900 globe valves are usually bolted bonnet design. And the Class1500~Class2500 globe valves are usually of pressurized seal design.

Actuation
Hand wheel, impact hand wheel and gear box is usually used for globle valve actuation. Chain wheel and electric acduator can be also used for globle valve actuation if being reguested by the customers.


Belleville spring loaded packing impacting system
If being requested by the customer, the Belleville spring loaded packing impacting can be adopted for enhancing the durability and reliability of the packing seal.

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

Seat
For carbon steek globe 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 globe 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 globe valves. For stainless steel globe valve, intergral seat is usually adopted, or to weld hard alloy directly intergrally. Threaded or welded on seat is also optional for stainless steel globe 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.

Stem nut
Usually, the stem nut is made of ASTM A439 D2. It is also can be made of copper ally if being requested by the customer. For large sized globe valve, rolling bearing is fitted at the two sides of stem nut in order to minimize the open and close torque of the globe valve.

Special globe valve
Besides the common globe valves, we also makes cryogenic globe valve, bellow sealed globe valve, Jacketed globe valve, etc.