What is the difference between K Series and L Series Spira-trol valves?

The K Series valves are rated for higher pressures (PN25/PN40) and are available in SG iron, carbon steel, and stainless steel. The L Series is designed for lower pressure applications (PN16) and includes cast iron as a body material option. K Series also offers an extended bonnet option for extreme temperature applications.

Which trim characteristic should I select for steam pressure control?

For most modulating steam control applications, the Equal percentage (E) trim (KE or LE valves) is recommended as it provides good control across a wide range of flowrates. Fast opening (F) trim is suitable only for on/off service, while Linear (L) trim is best for liquid applications with constant differential pressure.

What stem sealing option is recommended for high-temperature steam service above 200°C?

For temperatures above 200°C, graphite packing (option H) should be specified. For zero-emission requirements or temperatures up to 400°C (at PN25), the bellows seal option (D) with graphite secondary seals is recommended.

Can the Spira-trol valve achieve Class VI shut-off?

Yes, Class VI shut-off is achievable with soft seating options. PTFE seats are suitable up to 152°C, while PEEK seats (options C and P) extend the range to 220°C.

What actuators are compatible with Spira-trol valves?

The Spira-trol is designed to work with Spirax Sarco PN9000 series pneumatic actuators and AEL7 electric linear actuators. The valve-actuator assembly complies with Machinery Directive 2006/42/EC when these actuators are used.

SPIRAX SARCO · CONTROL VALVES

Spirax Sarco Spira-trol Two-Port Control Valves – EN Standard K & L Series DN15 to DN100

Name: Spirax Sarco Spira-trol Two-Port Control Valves – EN Standard K & L Series DN15 to DN100
Brand: Spirax Sarco

Spirax Sarco Spira-trol two-port globe control valves DN15-DN100 for modulating process control in steam, liquid & gas applications.

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Overview

The Spirax Sarco Spira-trol is a range of two-port, single-seat globe control valves with cage-retained seats, designed to EN 60534 standards. Available in DN15 to DN100 (½" to 4") sizes, these valves provide reliable modulating or on/off control when paired with pneumatic or electric linear actuators.

Built on a modular platform covering four body sizes (DN15-25, DN32-50, DN65-80, DN100), the Spira-trol series minimizes spare parts inventory while offering flexibility across applications. The valves are available in multiple body materials—cast iron, SG iron, carbon steel, and stainless steel—with various pressure ratings and connection types to suit diverse industrial requirements.

The Spira-trol control valve is CE marked and complies with the European Pressure Equipment Directive 2014/68/EU. Certification to EN 10204 3.1 is available upon request.

Key Features

Single-seat globe valve design with cage-retained seat for consistent performance
Modular construction reduces spare parts requirements across DN15-DN100 range
Multiple trim characteristics: Equal percentage (KE/LE), Fast opening (KF/LF), Linear (KL/LL)
Available in cast iron, SG iron, carbon steel, and stainless steel body materials
Stem sealing options: PTFE chevron (standard), graphite packing, or bellows seal for zero emissions
Soft seating options: PTFE (up to 152°C) or PEEK (up to 220°C) for Class VI shut-off
Extended bonnet option for high/low temperature applications (K Series)
Low noise and anti-cavitation trim available
Compatible with PN9000 series pneumatic and AEL7 electric actuators

Specifications

Parameter	Value
Sizes	DN15 to DN100 (½" to 4")
Design Standard	EN 60534
Pressure Ratings	PN16, PN25, PN40, JIS/KS10, JIS/KS20
Connection Types	BSP threaded (up to DN50), Flanged
Body Materials	Cast Iron (EN-GJL-250), SG Iron (EN-GJS-400-18), Carbon Steel (1.0460/1.0619N), Stainless Steel (1.4408)
Temperature Range (PTFE packing)	Up to 152°C (305.6°F)
Temperature Range (Graphite packing)	Up to 400°C (752°F) – PN25 with bellows
Temperature Range (PEEK seat)	Up to 220°C (428°F)
Trim Materials	431 SS, 316L SS, 316L SS with Stellite 6 facing
Threaded Connection Standard	BSP Taper Rp (ISO 7-1)
Compliance	PED 2014/68/EU, Machinery Directive 2006/42/EC (with actuator)
Certification Available	EN 10204 3.1
Series	Material	Screwed BSP	PN16 Flanged	PN25 Flanged	PN40 Flanged
L Series	Cast Iron	Up to DN50	DN15-DN100	—	—
L Series	Carbon Steel	—	DN15-DN100	—	—
L Series	Stainless Steel	—	DN15-DN100	—	—
K Series	SG Iron	Up to DN50	—	DN15-DN100	—
K Series	Carbon Steel	—	—	—	DN15-DN100
K Series	Stainless Steel	Up to DN50	—	—	DN15-DN100

Applications

Spira-trol control valves are suitable for modulating and on/off control in a wide range of industrial process applications:

- Steam systems – pressure and temperature control in boiler houses, process heating, and sterilization - HVAC systems – heating and cooling control in large commercial and industrial facilities - Process industries – flow and pressure regulation in chemical, pharmaceutical, and food processing plants - Power generation – feedwater and condensate control - Pulp and paper – steam and liquid flow control in drying and processing lines - Oil and gas – process control in refineries and petrochemical plants

Note: This product is not approved for direct food contact applications within the EU.

Frequently Asked Questions

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