GB Marine Gate Valve

Typical Specification Parameters

• Nominal Diameter (DN): DN6 to DN600 and even larger.

• Nominal Pressure (PN): 0.25 MPa, 0.4 MPa, 0.6 MPa, 1.0 MPa, 1.6 MPa, 2.5 MPa, etc. Some high‑pressure valves can go up to 4.0 MPa, 6.0 MPa, or 10.0 MPa.

• Applicable Media: Depending on the material, they can handle fresh water, seawater, lubricating oil, fuel oil, steam, and some corrosive chemicals.

• Flange Connection Dimensions: Generally follow standards such as GB/T 569 or GB/T 2501.

• Main Body Materials: Common materials include grey cast iron, cast steel, bronze, stainless steel, ductile iron, etc.

Overview

Main Features：

• Low fluid resistance: The internal passage of a gate valve is usually straight‑through, resulting in low fluid resistance and no restriction on flow direction.

• Relatively simple structure: Compared with other valve types, gate valves have shorter face‑to‑face dimensions and are relatively easy to manufacture.

• Sealing performance: The sealing surfaces are susceptible to erosion and wear from the medium, which may cause galling. Repair is relatively difficult.

• Operation and space requirements: Opening and closing are relatively labour‑saving, but the overall size is large, requiring considerable space for full opening, and the operating time is longer.Types and

Construction：

By stem thread position:

Rising stem gate valves (stem rises and is visible as the gate moves).

Non‑rising stem gate valves (stem does not move axially, only rotates).

By gate (disc) design:

Mainly divided into wedge‑type gate valves and parallel gate valves. Wedge‑type gate valves can be further subdivided into single‑gate, double‑gate, and resilient‑wedge types.

Common designations: Many standards classify products into types A, AS, etc., or A, B, AS, BS types.

Actuation methods: Mainly manual (handwheel), but can also be equipped with worm gear, electric motor, or bevel gear drives as required.

Main Standards and Model Designations：

Standard No.	Title	Key Features
CB/T 465-1995	Marine flanged cast iron gate valves	Body material: grey cast iron; low nominal pressure (0.25–0.6 MPa).
CB/T 466-1995	Marine flanged cast steel gate valves	Body material: cast steel; wider pressure range (0.25–1.0 MPa).
CB/T 467-1995	Marine flanged bronze gate valves	Body material: bronze; good seawater corrosion resistance; nominal pressure 0.25–0.6 MPa.
CB/T 3591-2005	Marine tanker gate valves	Specifically designed for oil tankers; nominal pressure 1.0 MPa.
GB/T 23300-2009	Flat gate valves	Specifies flanged flat gate valves, suitable for slurries, seawater, etc.
GB/T 44916-2024	Ships and marine technology – Marine ultra‑low temperature gate valves – Design and test requirements	Special gate valves for ultra‑low temperature environments (–196 °C to –50 °C).