Gate Valve

Pressure Seal

A pressure seal gate valve is a type of valve designed to withstand high pressures in industrial applications. It features a unique design where the body-bonnet joint is designed to seal under pressure from the fluid flow, enhancing the valve's sealing capability as the pressure increases.

Specifications

Gate Valve - Pressure Seal

Size Range

2 – 80 NPS, DN50 - DN2200

Body Materials

Carbon Steels, Low Temperature Carbon Steel, Martensitic Steels, Austenitic Stainless Steel, Duplex Stainless Steels, Super Duplex Stainless Steels, Nickel Alloys, Nickel Aluminum Bronze, Hastelloy, Inconel, Titanium Alloy & Carbon Steel with Internal Corrosion Resistant Alloy (CRA) Overlay

Temperature Range

-29°C to 1150°C

Trim Materials

Maximum Allowable Operating Pressure

ASME 150# to 2500#

Pressure-Temprature Rating

ASME B 16.34

Construction Details

Pressure Seal

Body Style

Flanged End, Butt Weld

Design Standard

API 600, BS 1414, API 6D

Flange Drilling

ASME B16.5

Testing Standard

API 598, API 6D, ISO 5208, API6FA, ISO 10497,BS6364

Face To Face

ASME B16.10

Applications

Refineries,Hydrocarbon,Energy and Process industries.

Operation

Handwheel, Gear, Actuator (Pneumatic, Hydraulic, Electro-Hydraulic and Electric Motorised)

Features:

Pressure Seal Design:
1. Unique design where the body-bonnet joint is designed to seal under high pressure.
2. The pressure from fluid flow enhances the sealing capability, providing a tighter seal as the pressure increases.
Rising Stem:
1. Typically features a rising stem design where the stem moves up and down with the gate, providing visual indication of the valve position.
2. The stem threads are isolated from the flow medium, reducing the risk of thread damage due to corrosion or erosion.
Solid Wedge Gate:
1. Gate valve design often includes a solid wedge gate that offers robust sealing capabilities.
2. Provides reliable shut-off by pressing into the seats, offering resistance to fluid pressure from both directions.
Materials:
1. Made from high-quality materials such as carbon steel, alloy steel, stainless steel, and exotic alloys (e.g., Monel, Inconel) to withstand corrosive environments and high temperatures.
2. Suitable material selection ensures durability and longevity under extreme operating conditions.
Bi-Directional Flow:
1. Capable of handling flow in both directions, making them versatile for various industrial applications.
Applications:
1. Widely used in industries such as power generation, oil and gas, petrochemicals, refining, and pipelines.Ideal for applications requiring high pressure ratings and reliable shut-off capabilities.

Benefits:

High Pressure Rating:
1. Designed to handle extremely high pressure ratings, often up to ANSI Class 4500 and beyond.
2. Suitable for critical applications where maintaining pressure integrity is essential.
Tight Shut-Off:
1. Provides a tight seal against fluid pressure from both directions, minimizing leakage and ensuring safe operation.
2. Enhanced sealing under high-pressure conditions due to the pressure seal design.
Reliability:
1. Robust construction and solid wedge gate provide reliability and durability in demanding environments.
2. Minimal maintenance required compared to other types of valves, contributing to operational efficiency.
Longevity:
1. Designed for long service life with minimal wear and maintenance requirements.
2. Resistant to wear and erosion in high-pressure and high-temperature environments.
Safety:
1. Ensures safe operation by reliably controlling fluid flow and providing secure shut-off capabilities.
2. Reduces the risk of leaks and potential hazards associated with high-pressure systems.
Versatility:
1. Suitable for a wide range of fluids including steam, water, oil, gases, and more.
2. Can be used in various applications where high-pressure sealing and reliable operation are critical.

FAQs:

How does a pressure seal gate valve differ from a bolted bonnet gate valve?

Design: Pressure seal gate valves have a self-sealing design where the pressure from the fluid enhances the seal, whereas bolted bonnet gate valves rely on bolts to secure the bonnet to the body.
Pressure Rating: Pressure seal gate valves are typically designed for higher pressure ratings, often exceeding ANSI Class 2500 and up to Class 4500 or higher, whereas bolted bonnet gate valves have lower pressure ratings in general.

What are the typical applications of pressure seal gate valves?

Pressure seal gate valves are used in industries where high-pressure and high-temperature applications are common, such as power generation (including nuclear power plants), oil and gas refining, petrochemical plants, pipelines, and other industrial processes requiring reliable shut-off under extreme conditions.

How are pressure seal gate valves maintained?

Maintenance involves regular inspection of sealing surfaces, lubrication of moving parts, and checking for any signs of wear or damage. The bonnet design allows for access to internal components for inspection and maintenance as needed.

Can pressure seal gate valves be used for throttling applications?

While pressure seal gate valves are primarily used for on/off service due to their design, they can be used for throttling applications in certain conditions where flow control is not critical and where erosion and cavitation are not concerns.

How do pressure seal gate valves prevent leakage?

Pressure seal gate valves prevent leakage by using the pressure from the fluid flow to enhance the seal between the body and bonnet. This self-sealing mechanism improves the valve’s sealing capability under high-pressure conditions, reducing the risk of leaks.