Gate valves

Gate valve types we manufacture

KTN manufactures the full gate valve range by connection and execution:

• ANSI flanged gate valves: class 150-300 to ASME B16.5, in WCB, AISI 316 and forged steel, for process plants built to American standards.
• DIN flanged gate valves: EN 1092-1 flanges PN10-PN40, the European standard for water, steam and process duty.
• NPT threaded gate valves: forged class 800 for small bore, instrument take-offs and drains.
• Butt weld and socket weld gate valves: forged class 800 with no dismountable joints, for steam, thermal oil and hydrocarbons.

Rising stem (OS&Y) or non-rising stem

A rising stem travels upwards with the wedge: valve position is readable from a distance and the thread sits outside the fluid, protected from corrosion. It needs headroom above the handwheel of roughly one extra nominal diameter. A non-rising stem rotates without translating and keeps overall height constant, which makes it mandatory in pits, trenches, suspended ceilings and congested pipe racks. In exchange, the thread runs immersed in the fluid and visual position indication is lost.

Solid wedge or flexible wedge

A solid wedge is one robust, economical piece, suited to water, saturated steam and general service. A flexible wedge carries a perimeter groove that lets it flex by a few hundredths of a millimetre and absorb body distortion caused by thermal expansion or flange bolt-up. Specify it for superheated steam, thermal oil and lines with wide thermal cycles, where a solid wedge can bind against the seats.

Materials and seats

KTN machines bodies from forged A105 and F316 in class 800, cast A216 WCB to API 600 and stainless steel AISI 316/316L. Forged steel has directional grain flow and no casting porosity, so it covers the most severe pressures and temperatures in small and medium bore. Cast bodies become more cost-effective from DN80 upwards and allow heavier wall sections. Seats are ground metal-to-metal and accept stellite or tungsten carbide hardfacing for abrasive fluids. Bolted bonnet, adjustable graphite gland packing and, on request, fugitive emission testing to ISO 15848.

Connections and standards

The range covers ANSI B16.5 flanges class 150-300, DIN EN 1092-1 flanges PN10-PN40, NPT thread to ASME B1.20.1, socket weld to ASME B16.11 and butt weld to ASME B16.25. Design follows API 600 for cast bodies, API 602 for compact forged class 800 and API 6D for pipeline execution. Check the DN to inches conversion table and the flange face types before closing a specification.

How to select a gate valve

• Function: confirm the duty is on/off isolation. Any throttling requirement rules the gate valve out.
• Connection: flanged when the valve must come out for maintenance; welded or threaded to remove leak paths at high pressure.
• Material: WCB for water and steam; AISI 316 for corrosives; forged A105 or F316 for higher classes.
• Pressure: class 150-300 or PN10-PN40 flanged, class 800 forged threaded and welded.
• Wedge and stem: measure headroom before choosing between OS&Y and non-rising stem; flexible wedge where thermal cycling occurs.
• Operation: direct handwheel on most sizes, gear operator where manual torque becomes excessive.

Applications and industries

KTN gate valves work in petrochemical, chemical, oil & gas, power generation, steam and thermal oil circuits, water treatment and desalination, pulp and paper, mining, marine and HVAC. They stay open on main lines and close to isolate a pump, a vessel or a section during a maintenance shutdown.

Buying gate valves direct from the manufacturer

Buying from KTN means buying at the factory gate, with no distributor in between. KTN holds stock of the most common materials and sizes for immediate despatch, issues a certificate of origin with every order and manufactures special executions to drawing. Send DN, pressure class, body material, connection, fluid and service temperature and the technical team returns a quotation with price and lead time. Distributor enquiries are welcome.

Why KTN

KTN Valves (Kara Technology News, S.L.) is a manufacturer with its head office and plant in Rubí, Barcelona. Production runs in its own facilities under an ISO 9001 quality system, with Bureau Veritas inspection, a certificate of origin on every shipment and 3.1 material certificates on request. Valves are made in Spain.

Related categories

For flow regulation, see globe valves. For quarter-turn shut-off, ball valves. For economical large bore isolation, butterfly valves. To stop reverse flow, check valves. The full range is under industrial valves.

Frequently asked questions

Can a gate valve be used to throttle flow?

No. A gate valve works fully open or fully closed. Part-open, the wedge chatters against its guides and the jet erodes the seat, so the valve stops sealing. For flow regulation, specify a globe valve or a control valve, both designed to operate partly open with a hardfaced trim.

Cast WCB or forged class 800 gate valve?

Cast A216 WCB to API 600 covers general service and becomes more cost-effective from DN80 upwards. Forged A105 or F316 class 800 to API 602 has directional grain flow and no casting porosity, so it withstands higher pressures and temperatures in small and medium bore, typically threaded or welded.

Rising stem OS&Y or non-rising stem?

A rising stem shows valve position at a glance and keeps the thread out of the fluid, but needs headroom above the valve of roughly one extra nominal diameter. A non-rising stem keeps overall height constant and wins in pits, trenches and congested pipe racks, at the cost of visual position indication.

When is a flexible wedge needed instead of a solid wedge?

Specify a flexible wedge where the line sees wide thermal cycles: superheated steam, thermal oil, or frequent start-ups and shutdowns. Its perimeter groove absorbs body distortion and prevents the wedge from binding in the seats. For water, saturated steam and general service, a solid wedge is sufficient and cheaper.

Do you hold stock and what does a gate valve cost?

KTN holds the most common materials and sizes in stock for immediate despatch. Price depends on DN, pressure class, body material and connection. Buying direct from the manufacturer removes the distributor margin. Request a quotation stating DN, class, material and service conditions, and KTN returns price and lead time.

Request a quotation

Ask KTN for gate valve pricing direct from the factory. State DN, pressure class, material, connection, fluid and temperature and KTN returns a tailored offer with price and lead time. Phone +34 937 818 219, email ktn@ktnvalves.com, 8:00 to 19:00.