Product Overview

DEENPU Model M Expanding Gate Valve — 3D Cross-Section Showing Internal Components

The DEENPU Model M Series Expanding Gate Valve is a high-performance, API 6A compliant gate valve designed for wellhead, manifold, and production system applications in the oil and gas industry. The valve features a unique expanding gate design consisting of a gate body and a related segment, with the middle contact surface precision-machined to a milled V-Structure. This expanding mechanism ensures a tight, pressure-assisted seal between the gate and seats in both the open and closed positions, providing reliable shutoff and long service life in demanding oilfield conditions.

DEENPU Model M Gate Valves are available in bore sizes from 2-1/16″ through 7-1/16″ and working pressures from 2,000 PSI (2M) through 5,000 PSI (5M), covering the full range of standard API 6A wellhead and manifold applications. The valve is available with both threaded end and flanged end connections, with dimensions and pressure ratings compliant with API 6A and ASME B16.5 standards. The non-rising stem design minimizes the operational space required above the valve, while the upper and lower roller thrust bearings significantly reduce the operating torque required to open and close the valve under pressure.

Each valve is designed and manufactured to meet or exceed API 6A specification requirements, with full material traceability, hydrostatic testing, and comprehensive inspection documentation. The seats are fitted with grease injection fittings for in-service lubrication, reducing abrasion and extending the service life of the sealing surfaces. DEENPU Model M Gate Valves are suitable for both sweet (general) service and sour service (H2S) applications when manufactured with appropriate material grades and NACE MR0175 compliance.

How the Model M Expanding Gate Valve Works

The Model M expanding gate valve operates through a unique mechanism that provides superior sealing performance compared to conventional wedge gate valves:

1. Expanding Gate Mechanism — The valve consists of two main components: the gate body and the gate segment. The contact surface between the gate body and segment is machined to a precision V-Structure. When the valve is in the closed position, the gate is positioned between the two seats, and the internal pressure of the fluid acts on the gate to push the gate body and segment apart, expanding the gate against the seats. This pressure-assisted expansion creates a tight, bubble-tight seal that improves as the line pressure increases. The V-Structure design ensures that the expansion force is evenly distributed across the full sealing surface, preventing localized wear and ensuring consistent sealing performance over thousands of cycles.
2. Non-Rising Stem Operation — The Model M features a non-rising stem design, meaning the stem does not move vertically out of the valve bonnet when the valve is opened or closed. Instead, the stem rotates, and the gate moves up and down internally. This design provides several advantages: it minimizes the vertical space required above the valve, making it ideal for installations with limited overhead clearance (such as on offshore platforms and in crowded manifold assemblies); it prevents the stem from being exposed to the external environment, reducing the risk of corrosion and contamination; and it allows the valve to be operated in any orientation without the stem protruding. The non-rising stem is threaded into the gate and guided by a stem nut in the bonnet, with the upper and lower roller thrust bearings carrying the axial load and minimizing friction.
3. Seat Lubrication and Wear Protection — The valve seats are equipped with grease injection fittings that allow the injection of seat lubricant (typically a valve sealant or lubricant compound) directly into the seat area. This lubrication serves three purposes: it reduces the friction between the gate and seats during operation, lowering the operating torque; it protects the sealing surfaces from abrasion and galling, particularly in applications with abrasive fluids or sand production; and it provides a secondary seal that can help maintain tight shutoff even if the primary metal-to-metal seal shows minor wear. The grease injection system can be serviced while the valve is in line, without requiring valve removal or system shutdown. Regular lubrication is recommended as part of the valve maintenance program to ensure long-term reliable performance.

Key Features

Applications

• Wellhead production valves — Master valve, wing valve, and swab valve on Christmas trees and wellhead assemblies for production flow control
• Choke and kill manifolds — Isolation valves on choke manifold, kill manifold, and well control system piping for high-pressure shutoff
• Production manifolds — Flowline isolation, header valves, and test line valves on production and test manifold systems
• Water injection systems — High-pressure isolation valves on water injection wellheads and injection manifold systems
• Gas lift systems — Gas lift manifold valves, gas supply line valves, and wellhead gas lift valves
• Well testing and workover — Temporary and permanent valves on test manifolds, workover BOP stacks, and well service lines
• Offshore platform wellheads — Compact, low-overhead valves on platform wellheads, subsea wellheads, and FPSO turret manifolds
• Gas processing and transmission — High-pressure isolation on gas gathering lines, compressor station piping, and gas processing plant headers

Threaded End Model M Gate Valve Dimensions — 2,000 PSI

Threaded end connections: API line pipe or tubing threads. A = Thread face to face. B = Bore centerline to bottom of valve. C = Bore centerline to hand wheel top. D = Hand wheel diameter. All dimensions per API 6A. Contact us for non-standard sizes and custom configurations.

Threaded End Model M Gate Valve Dimensions — 3,000 PSI

Threaded End Model M Gate Valve Dimensions — 5,000 PSI

Flanged End Model M Gate Valve Dimensions — 2,000 PSI

Flanged end connections: API 6B or 6BX flanges. A = Flange face to face. B = Bore centerline to bottom of valve. C = Bore centerline to hand wheel top. D = Hand wheel diameter. Ring gasket type: BX for 6BX flanges, RX for 6B flanges. All dimensions per API 6A.

Flanged End Model M Gate Valve Dimensions — 3,000 PSI

Flanged End Model M Gate Valve Dimensions — 5,000 PSI

All dimensions approximate per API 6A 21st Edition. Flange face-to-face dimensions vary with flange type (6B vs 6BX) and ring gasket type. Weights shown are approximate for standard carbon steel construction. Contact us for exact dimensions, weights for alternative materials (stainless steel, duplex, etc.), and custom configurations.

When Ordering, Please Specify

1. Valve SizeStandard bore sizes: 2-1/16″, 2-9/16″, 3-1/8″, 4-1/16″, or 7-1/16″. Custom sizes available on request.
2. Working Pressure Rating2M (2,000 PSI), 3M (3,000 PSI), or 5M (5,000 PSI). Select based on maximum anticipated operating pressure.
3. End Connection TypeThreaded end (API line pipe or tubing thread) or flanged end (API 6B or 6BX flange). Specify thread type or flange size and pressure rating.
4. Ring Gasket Type (for flanged valves)BX (for 6BX flanges), RX (for 6B flanges), or R (for type 6B flanges). Specify based on mating flange configuration.
5. Material GradeAPI 6A material grade: AA, BB, CC, DD, EE, FF, or HH. For sour service, specify NACE MR0175 compliant grade. For low-temperature service, specify impact test requirements.
6. Material SpecificationCarbon steel (AISI 4130/4140), low-alloy steel, or stainless steel (duplex, super duplex). Specify for corrosive or high-temperature environments.
7. Stem ConfigurationNon-rising stem (standard for Model M). Rising stem available on special request. Specify handwheel or chainwheel operator.
8. Operator TypeHandwheel (standard), chainwheel (for elevated installations), gear operator (for high-torque or motor actuation), or pneumatic/hydraulic actuator.
9. Service ConditionGeneral (sweet) service or Sour Service (H2S). Specify H2S partial pressure, CO2 content, and temperature for sour service material selection.
10. Certification RequirementsAPI 6A certification, material test certificates (MTC), hydrostatic test certificates (shell and seat), NACE MR0175 compliance certificate, and third-party inspection (DNV, BV, SGS).

Custom Manufacturing & OEM Capability

• Non-Standard Sizes — Custom bore sizes, face-to-face dimensions, and overall dimensions manufactured to customer specifications for retrofit and replacement applications.
• Special Material Grades — Duplex stainless steel (2205, 2507), super duplex, Inconel, Monel, and other corrosion-resistant alloys for extreme sour service and high-temperature applications.
• Actuator-Ready Configuration — Valve prepared for pneumatic, hydraulic, or electric actuator mounting with ISO 5210 mounting flange, stem extension, and position indicator.
• Locking and Safety Devices — Stem locking devices, mechanical stop locks, and safety interlocks for critical isolation applications where accidental operation must be prevented.
• Extended Bonnet / Cryogenic Service — Extended bonnet design for cryogenic service, LNG applications, and extreme cold environments to prevent stem packing freeze-up.
• Special Coating and Surface Treatment — Internal cladding (Inconel 625 or 316L overlay), PTFE coating, epoxy coating, or hard chrome plating for corrosion resistance and reduced friction.
• Special Testing — Gas testing (helium or nitrogen leak test), cryogenic testing, fire-safe testing (API 6FA), and high-cycle endurance testing beyond standard API 6A requirements.
• Complete Valve Package — DSA supplied as part of a complete wellhead assembly including casing heads, tubing heads, Christmas trees, valves, and manifolds.

Quality Control & Testing Standards

• Material chemical composition verified per heat. Carbon, manganese, chromium, nickel, molybdenum, and sulfur content verified against API 6A material grade requirements.
• Material mechanical properties tested per heat including tensile strength, yield strength, elongation, and hardness per API 6A.
• Impact testing at specified temperature for low-temperature service per API 6A and ASTM A370.
• Each valve shell hydrostatically tested to 1.5x rated working pressure per API 6A. Hold time and leak rate recorded on test certificate.
• Each valve seat hydrostatically tested to 1.1x rated working pressure in both directions. Zero leakage acceptance criterion.
• Gas seat test (optional) at 80% of rated working pressure using nitrogen or helium for critical applications. Leak detection by bubble test or pressure decay.
• Dimensional inspection of bore diameter, face-to-face dimension, flange dimensions, handwheel diameter, and overall height per API 6A tolerances.
• Gate and seat contact surface inspection with dye penetrant or magnetic particle inspection to verify integrity of sealing surfaces.
• Stem thread and thrust bearing inspection for proper fit, torque, and smooth rotation.
• Material test certificates (MTC) per EN 10204 3.1 provided for all valve body, bonnet, gate, and stem materials.
• Third-party inspection and certification by DNV, BV, SGS, or ABS available upon request.

Frequently Asked Questions