Control valves
A control valve regulates flow, pressure or temperature by holding the closure member in intermediate positions instead of just open or closed. KTN Valves manufactures high pressure needle and control valves in Rubí (Barcelona, Spain), and automates globe, ball and butterfly valves with actuator and positioner.
Filter
Showing the single result
Ask a quotation
Request a quote for control valves: tell us the DN, material, mounting type (wafer, lug or clamp), seat, pressure and temperature and we will send you a customized offer with the best price and lead time.
Control valves
CONTROL VALVE GENERAL DESCRIPTION
Item | KTN control valves |
|---|---|
Manufacturer | KTN Valves (Kara Technology News, S.L.), own factory in Rubí, Barcelona, Spain |
Types | High pressure needle and control valve; actuated globe, ball and butterfly valves with positioner; pneumatic angle seat valve |
Materials | Stainless steel AISI 316/316L, carbon steel WCB, forged steel A105/F316; PTFE seals and seats |
End connections | NPT thread (ASME B1.20.1) and BSP (ISO 228), ANSI B16.5 flange class 150-300, DIN EN 1092-1 flange PN10-PN40, wafer |
Sizes | Needle valve in small threaded sizes; actuated versions follow the DN of the base valve |
Pressure and temperature | Up to 3,000 psi (207 bar) and −54 °C to +250 °C on the high pressure needle valve |
Standards | ISO 5211, ANSI/FCI 70-2 class VI, ASME B1.20.1, ASME B16.5, EN 1092-1 |
Certification | ISO 9001, Bureau Veritas inspection, certificate of origin, 3.1 material certificate on request |
What a control valve is and when to use one
A control valve modulates flow continuously from a loop signal, typically 4-20 mA. It runs at part opening without eroding the seat or chattering, which an on/off valve cannot do. The relationship between travel and flow sets the flow characteristic: linear for flow loops, equal percentage for pressure and temperature loops, quick opening for fast on/off duty.
Control valve types we manufacture
KTN covers modulating duty two ways: a dedicated high pressure valve, and shut-off valves automated with a positioner.
- High pressure control valves (needle type): tapered stem and NPT thread up to 3,000 psi for fine metering, instrumentation and sampling.
- Actuated globe valves: in-line plug with stellite faced seat for throttling steam and process lines.
- Ball valves with actuator and positioner: quarter-turn modulation with tight shut-off.
- Actuated butterfly valves: the cost-effective answer in large water and air lines.
- Pneumatic angle seat valve: single acting, straight flow path and minimum pressure loss for viscous fluids.
Materials and seats
KTN machines bodies in stainless steel AISI 316/316L, carbon steel WCB and forged steel A105/F316. The high pressure needle valve runs in stainless steel with PTFE seals from −54 °C to +250 °C. For steam and erosive service the seat is hard faced with stellite or tungsten carbide, because cavitation destroys the trim long before the body. A lapped metal-to-metal seat reaches class VI of ANSI/FCI 70-2.
Connections and standards
The needle valve connects with NPT thread to ASME B1.20.1. Actuated versions keep the end connection of the base valve: ANSI B16.5 flange class 150-300, DIN EN 1092-1 flange PN10-PN40, BSP thread to ISO 228, socket weld or butt weld ends to ASME B16.11 / B16.25, or wafer mounting. Every quarter-turn valve carries an ISO 5211 top flange for the actuator. Fix the size with the DN to inches conversion table.
How to select a control valve
Decide in this order: function (isolate or modulate), flow range and characteristic, line connection, material for fluid and temperature, pressure class, seat and valve automation. The actuator is sized by torque, the positioner turns the 4-20 mA signal into travel, and the limit switch box reports position to the PLC.
An actuated ball or butterfly valve with positioner solves slow loops: tank level, blending or the temperature of a water circuit. It adds tight shut-off and costs less. Where the loop needs high rangeability, stable control near the seat or a high pressure drop, the answer is a dedicated needle valve or an actuated globe valve.
Applications and industries
KTN supplies control valves for instrumentation and sampling, compressed air, steam and thermal oil, petrochemical, chemical, oil & gas, power generation, water treatment and desalination, food and pharmaceutical plants. For acid dosing KTN works in 316L stainless steel and PTFE lined executions.
Buying direct from the manufacturer
Buying from the factory removes the distributor margin and shortens specification. KTN keeps common sizes and materials in stock for immediate despatch, issues a certificate of origin with every order and produces special executions to drawing. Send fluid, flow rate, differential pressure, temperature and control signal to get a made-in-Spain quotation with the assembly mounted. Distributor enquiries are welcome.
Why KTN
KTN Valves (Kara Technology News, S.L.) is a Spanish valve manufacturer based in Rubí, Barcelona, producing in its own facilities under an ISO 9001 quality system with Bureau Veritas inspection. Each order ships with a certificate of origin and, on request, a 3.1 material certificate. The engineering team closes the specification and tests the valve and actuator assembly before despatch.
Related categories
For in-line throttling with a hard faced seat, see globe valves. For quarter-turn shut-off, see ball valves and butterfly valves. Actuators, NAMUR solenoid valves and limit switch boxes are in valve automation, loop gauges and transmitters in instrumentation, and the full range in industrial valves.
Frequently asked questions
What is the difference between a control valve and a shut-off valve?
A shut-off valve works open or closed and its seat erodes if left part open. A control valve holds intermediate positions in a stable, repeatable way, with a defined flow characteristic and a 4-20 mA signal that sets travel.
Can I throttle flow with an actuated ball or butterfly valve?
Yes, where the loop is slow and the pressure drop moderate: tank level, blending or the temperature of a water circuit. The actuator mounts on the ISO 5211 interface with a 4-20 mA positioner. For high rangeability use a needle valve or an actuated globe valve.
What pressure and temperature does the high pressure needle valve handle?
The KTN needle valve with NPT thread works up to 3,000 psi (207 bar) and from −54 °C to +250 °C, in stainless steel with PTFE seals. It is the standard choice for instrumentation, gauge blow-down and sampling points on high pressure lines.
What does a positioner do and when is it needed?
A positioner compares the loop signal with the real stem position and corrects the air pressure until they match. It is needed whenever the valve modulates: without it, the actuator only travels fully open or fully closed.
How do I request a control valve quotation?
Send fluid, minimum and maximum flow, inlet and outlet pressure, temperature, line connection and control signal. KTN sizes the trim and the actuator and issues a factory quotation. Common configurations ship from stock.
Request a quotation
Send fluid, flow rate, differential pressure, temperature, line connection and control signal and KTN prepares a factory quotation with the assembly mounted and tested. Request a quotation or call +34 937 818 219.