Specification

High Quality Manual Flat Carbon Steel Hard Seal Gate Valve

I. Product Overview

NEWWAY manual flat gate valves are designed for precise flow control in industrial pipelines, adhering to GB/T 12234 standards. Featuring a flat gate design and flange connection, these valves are crafted from high-quality carbon steel (WCB) or stainless steel (304/316), offering reliable shut-off capabilities for various media, including water, steam, oil, and gas. With nominal diameters ranging from DN50 to DN600 and pressure ratings up to PN16, these valves are suitable for diverse applications in chemical, petroleum, power generation, and water treatment industries.

II. Core Technical Specifications

Nominal Diameter & Pressure Rating

Size Range: DN50-DN600 (2”-24”)

Pressure Class: PN10/PN16 (1.0MPa/1.6MPa)

Temperature Range: -29°C to 425°C (carbon steel); -196°C to 600°C (stainless steel)

Materials & Construction

Body & Bonnet: WCB (carbon steel), CF8 (304 stainless steel), CF8M (316 stainless steel)

Gate & Seat: 1Cr13/2Cr13 stainless steel with hardfacing (carbon steel models); SS304/316 (stainless steel models)

Stem: 2Cr13 stainless steel, anti-corrosion treatment

Packing: Flexible graphite, PTFE, or asbestos-free materials

Gasket: Spiral-wound gasket (SS304+graphite)

Connection & Operation

Flange Standard: ASME B16.5, GB/T 9113, DIN 2501

End Connection: RF (raised face) or FF (flat face)

Operation Mode: Manual handwheel or bevel gear drive

Product Overview

III. Design Features & Advantages

Flat Gate Structure

Full-bore design minimizes flow resistance (Cv value up to 30% higher than conventional gate valves)

Parallel seat design ensures bidirectional sealing with zero leakage

Anti-friction graphite coating reduces operating torque by 25%

Robust Sealing System

Metal-to-metal sealing with STL alloy overlay on seats (hardness ≥HRC45)

Secondary soft seal (NBR/PTFE) provides redundant sealing under low pressure

Stem sealing with V-ring packing, tested to 10,000 cycles without leakage

Reliable Stem Design

Non-rising stem with trapezoidal thread (ACME thread form)

Thrust bearing reduces friction during operation

Anti-blowout stem design ensures safety under high pressure

IV. Manufacturing Process & Quality Control

Precision Casting

Investment casting for complex components with dimensional accuracy ≤±0.5mm

Ultrasonic testing (UT) and magnetic particle inspection (MPI) for defect detection

Heat treatment (normalizing/tempering) to enhance material properties

Advanced Machining

CNC machining centers ensure surface roughness Ra≤3.2μm

Seat sealing surface ground to flatness ≤0.02mm

Stem thread pitch accuracy ≤±0.01mm

Stringent Testing

Hydrostatic test: 1.5x working pressure for shell, 1.1x for sealing (30-minute hold time)

Gas tightness test with nitrogen at 0.6MPa

Low-temperature test (-46°C) for cryogenic applications