Gate Valves

Gate Valve Selection — Quick Reference

Gate valves are designed for FULLY-OPEN or FULLY-CLOSED service — NEVER for flow throttling (causes erosive wear of the gate). Selection turns on body material, connection type (threaded/flanged), pressure rating, and service media.

Critical: Gate valves require FULL stem rotation to fully open or close — partial open = vibration + wear + erosion of seat. NEVER use as flow control (use ball or globe valve instead). Rising stem = visible position; non-rising = compact (no overhead clearance). Brands: AAP, Dixon. Companion: ball valves, butterfly valves, butterfly valve guide, pipe fittings.

Gate Valves

AIMS Industrial sells 40+ gate valves from AAP and Dixon — covering bronze screwed gate valves, brass general-purpose gate valves, cast iron non-rising and rising stem gate valves (Table D and Table E), stainless steel gate valves, knife gate valves for slurry applications, resilient-seated gate valves, and forged and cast steel flanged gate valves to ANSI 150. BSP threaded and flanged connections available across the range.

AAP Gate Valve Range

AAP is the primary gate valve brand in this collection, stocking the full range of industrial gate valve types from standard bronze screwed to high-pressure forged steel class 800.

• AAP Bronze Gate Valve — Screwed BSP — bronze (gunmetal) screwed gate valve for water supply, fire services and general process piping. Excellent corrosion resistance; standard in building services and fire systems.
• AAP Brass Gate Valve — General Purpose — brass gate valve for general-purpose water and fluid isolation. Cost-effective for standard plumbing and irrigation applications.
• AAP Cast Iron Gate Valve — Non-Rising Stem, Table D — cast iron non-rising stem gate valve to AS 2638 Table D for large-bore water mains, fire systems and industrial plant. Non-rising stem suits restricted headroom applications.
• AAP Cast Iron Wedge Gate Valve — Rising Stem, Table E — rising stem variant; stem position provides a visual open/closed indicator. Used where headroom allows and valve position confirmation is required.
• AAP Resilient Gate Valve with Spindle Cap — Table C — resilient-seated gate valve with epoxy-coated ductile iron body for water authority and municipal water supply applications.
• AAP Stainless Steel Gate Valve — stainless steel gate valve for corrosive process fluids, food-grade systems, chemical plant and marine applications where cast iron or brass would corrode.
• AAP Stainless Steel Knife Gate Valve — Clockwise Close — knife gate valve for slurry, pulp, wastewater and mining applications. The knife-edged gate cuts through viscous and fibrous media that would jam a standard gate valve.
• AAP Forged Steel Gate Valve — Socket Weld, Class 800 — forged steel class 800 gate valve with socket weld ends for high-pressure steam and process lines.
• AAP Forged Steel Gate Valve — NPT Thread, Class 800 — class 800 forged steel with NPT threaded connections for high-pressure process piping systems.
• AAP Cast Steel Flanged Gate Valve — ANSI 150 — cast steel flanged gate valve to ANSI 150 for process plant, refineries and pipeline isolation where flanged connections are specified.

Dixon Gate Valves

Dixon supplements the AAP range with cast iron and ductile iron flanged gate valves and DZR-tested brass screwed valves.

• Dixon Cast Iron Gate Valve — Wedge Flanged — cast iron flanged wedge gate valve for general industrial isolation applications.
• Dixon Brass Gate Valve — DZR Tested, Screwed Female BSP — dezincification-resistant (DZR) brass gate valve for potable water applications where dezincification of standard brass is a concern.
• Dixon Flanged OS&Y Gate Valve — outside screw and yoke (OS&Y) flanged gate valve; rising stem provides clear open/closed visual indication for fire and process applications.
• Dixon Ductile Iron Flanged Gate Valve — ductile iron flanged gate valve with greater strength and impact resistance than standard grey cast iron.

Gate Valve vs Ball Valve — Selection Guide

• Gate valves are preferred in large-bore piping (DN50 and above) for full-bore, low-resistance isolation. The straight-through gate opening creates minimal turbulence and pressure drop in the fully-open position.
• Non-rising stem gate valves are required where headroom above the valve is restricted. Rising stem valves provide visual open/closed confirmation via stem position — specified in fire systems and critical isolation points.
• AAP cast iron Table D gate valves comply with AS 2638 for fire protection and municipal water supply — the standard specified by water authorities and fire engineers for mains water isolation.
• Knife gate valves are designed specifically for slurry, pulp and solids-bearing flows. Standard gate valves will jam and fail in these applications.
• Forged steel class 800 gate valves are required for high-pressure steam, gas and process lines where cast iron and brass would be unsuitable.

Shop the full range above, or contact our team for expert advice on the right product for your application or reach out if you need a quote. Fast dispatch from our Australian warehouse.

Australian Business, Local Supply: AIMS Industrial has supplied Australian industry since 1988.

Also see our Ball Valves, Butterfly Valves and Check Valves ranges.

People Also Ask — Gate Valves

Q: When should I use a gate valve vs a ball valve?

Gate valves are for ON/OFF isolation only — they shouldn't be throttled (partially open) because the gate flutters and erodes the seat. They provide unrestricted full-bore flow when open and tight shutoff when closed. Ball valves are quicker to operate (90-degree turn) and can throttle. Gate valves suit slow-acting main isolation; ball valves suit frequent or partial operation. Don't substitute one for the other.

Q: What's the difference between rising stem and non-rising stem gate valves?

Rising stem (RS) gate valves have a stem that lifts visibly as the valve opens — easy to see at a glance whether the valve is open or closed. Non-rising stem (NRS) have the threaded section inside the bonnet, with only the handwheel visible — no external stem movement. Rising stem is preferred where you can see the valve (workshop, exposed pipe runs); non-rising stem is used in tight spaces or buried installations where stem movement isn't possible.

Q: What pressure rating do I need?

Class 125, 150, 200, 300 lb are common pressure ratings — corresponding to maximum working pressures from about 8 bar to 50 bar at moderate temperatures. The class rating reduces at elevated temperatures (refer to the manufacturer's pressure-temperature chart). For workshop water and compressed air, Class 125 is usually adequate; for higher pressure or steam, step up to Class 200 or 300. Always verify the pressure-temperature combination meets your service.

Q: Brass, bronze, cast iron, or stainless gate valves?

Brass for water and compressed air up to about 200°C and moderate pressure. Bronze for marine and slightly more aggressive service. Cast iron for water service in industrial systems (low pressure but cost-effective for large sizes). Stainless steel for steam, chemicals, food, and pharmaceutical service. Match the material to the fluid, pressure, temperature, and ambient corrosion exposure.

Q: Why is my gate valve leaking through when closed?

Common causes: debris stuck on the seat (open and close the valve fully to flush, then try sealing again), seat damage (gate has scored the seat from previous debris or throttling — needs valve replacement or seat lap), packing leakage at the stem (re-pack or replace), or thermal cycling has loosened the stem packing nut. For workshop systems, sometimes a quick valve replacement is more cost-effective than disassembly and repair.