Globe valves

What a globe valve is and what it is used for

The globe valve is the reference manual throttling valve in steam and process lines. Its seat sits parallel to the flow axis and the disc lowers perpendicular onto it, so the annular flow area changes progressively with stem travel. That linear movement lets an operator set an intermediate flow and repeat it, which a quarter-turn valve cannot do.

The hydraulic cost is real. Fluid follows an S path inside the body to pass the seat, so a globe valve produces far more pressure drop than a gate or ball valve of the same DN, even fully open. It also seals tight and can isolate, although fitting a globe valve purely to shut off means paying that pressure drop for the life of the line.

Decision summary: to throttle, globe; for fast shut-off with no pressure drop, ball; to isolate large bore, gate. Throttling with a gate valve erodes the wedge within a few cycles.

Globe valve types we manufacture

KTN builds globe valves by connection and pressure class:

• ANSI flanged globe valves: ASME B16.5 class 150-300 throttling, with stellite seat.
• DIN flanged globe valves: EN 1092-1 PN16-PN40, with bellows option.
• NPT threaded globe valves: forged class 800 for small bore and instrumentation.
• BW/SW welded globe valves: forged class 800 for steam and high pressure.

Two bonnet designs are available. The bolted bonnet is removed to service the disc and packing without cutting the pipe. The yoke bonnet forms a stiffer single assembly, cuts leak paths and is preferred in high pressure and steam.

Materials and trim

KTN machines the body from forged A105, forged F316, AISI 316 and cast WCB. Forged class 800 covers small bore at high pressure; cast bodies cover the flanged sizes. In carbon steel the usual service range runs from −29 °C to 425 °C, with higher figures in stainless steel according to specification.

Seat and disc are ground and, for erosive duties, hardfaced with stellite. That hard alloy resists the erosion and cavitation that appear when the valve works partially open on steam or condensate. For toxic, flammable or high value fluids KTN supplies a bellows sealed version, which encloses the stem and removes leakage through the packing; fugitive emissions can be certified to ISO 15848 on request.

Connections and standards

KTN produces globe valves with ASME B16.5 flanges (class 150-300), EN 1092-1 flanges (PN16-PN40), NPT threads to ASME B1.20.1 and welded ends to ASME B16.11 socket weld or ASME B16.25 butt weld. The forged range follows API 602, the standard for small bore forged steel valves, whose scope reaches DN100. Class 800 is its intermediate rating: more allowable pressure than class 600 with the wall thickness of a class 1500 body.

To match European and American sizes and flange facings, use the KTN DN to inches conversion table and the guide to flange face types.

How to select a globe valve

• Function: manual throttling calls for a globe valve. For a continuous automatic loop, move to the control valve range.
• Connection: flanged to dismantle for maintenance, BW/SW welded for high pressure and steam, NPT threaded on small branches.
• Class and material: forged class 800 at high pressure, cast WCB or AISI 316 in flanged sizes.
• Trim: stellite seat whenever the valve will run partially open on steam or erosive media.
• Stem sealing: graphite packing for general service, bellows for hazardous fluids.

Flow direction on installation

A globe valve is directional and the body carries a cast arrow. Standard practice in manual service is flow under the disc: pressure assists opening, handwheel effort drops and, with the valve closed, the packing sees no pressure, so it can be replaced without depressurising the whole line. Some high temperature steam designs specify flow over the disc instead; KTN confirms the direction on the drawing of each execution. Fitting the valve the wrong way round causes disc chatter, stem vibration and early seat wear.

Applications and industries

KTN supplies globe valves to steam and thermal oil, power generation, oil and gas, petrochemical, chemical and process lines where flow is throttled or a drain is trimmed. The forged welded execution is standard on instrument branches and high pressure drains.

Buying direct from the manufacturer

Buying from KTN removes the middleman: factory pricing, a quotation closed against your service conditions and full material traceability. KTN keeps common configurations in stock for immediate despatch and manufactures special executions to drawing, with bellows, stellite trim or specific materials. Distributor enquiries are welcome.

Why KTN

KTN Valves (Kara Technology News, S.L.) is a Spanish manufacturer based in Rubí, Barcelona, producing in its own plant under an ISO 9001 quality system with Bureau Veritas inspection. Every order ships with a certificate of origin and, on request, a 3.1 material certificate. KTN is appointing distributors in France, the United Kingdom, Poland and Vietnam.

Related categories

Quarter-turn shut-off: ball valves. Full bore isolation: gate valves. Low cost shut-off between flanges: butterfly valves. Backflow prevention: check valves. Full range at industrial valves.

Frequently asked questions

Can a globe valve be used for shut-off?

Yes, a globe valve seals tight and isolates the line. The drawback is hydraulic: the flow turns inside the body and creates a permanent pressure drop even when fully open. For pure isolation a ball valve or a gate valve is cheaper to run, because both leave a clear bore.

Globe or gate valve for throttling?

Globe. The globe valve is designed to run partially open and accepts stellite hardfacing on the seat. A gate valve at half lift chatters, erodes the wedge and ruins the seal within a few cycles. The gate valve belongs in full open or full closed service, where its pressure drop is minimal.

Which way round is a globe valve installed?

Follow the arrow cast on the body. Manual service normally uses flow under the disc: it lowers the opening effort and leaves the packing unpressurised when the valve is closed. Some steam duties specify flow over the disc. Fitting it the wrong way round causes vibration and premature seat wear.

What do class 800 and API 602 mean?

API 602 is the standard for small bore forged steel valves, with a scope up to DN100. Class 800 is its intermediate pressure rating: it allows more pressure than class 600 while using the wall thickness of a class 1500 body. KTN manufactures it in A105 and F316, NPT threaded or BW/SW welded.

Do you hold stock and how is a globe valve priced?

KTN keeps the most common combinations of material, class and connection in stock for immediate despatch. Price depends on DN, pressure class, body material and trim. Buying direct from the manufacturer removes the distributor margin. Send your service conditions and you will receive a firm quotation.

Request a globe valve quotation

Send DN, pressure class, connection, fluid, temperature and whether the valve will run partially open, and KTN engineering will size the trim and prepare a tailored offer. Call +34 937 818 219 or write to ktn@ktnvalves.com.