Description
1½" Bronze Steam Solenoid Valve – Queen MK40S
The Queen MK40S is a heavy-duty 1½" 2/2 way normally closed bronze steam solenoid valve designed for reliable control of steam, hot and cold water, oils, air, vacuum and compatible industrial gases and fluids.
Featuring an assisted-lift / kick-pilot design, the MK40S combines high flow capacity with operation from very low differential pressure. The valve remains closed when de-energised and opens when electrical power is applied.
Manufactured with a robust BC6 bronze body, stainless steel internal components and PTFE sealing, the MK40S features a large 43mm orifice providing 257.4 L/min water flow at 1 Bar pressure difference. It is particularly suited to industrial steam distribution, boiler plant and process heating applications.
Valve Function & Operation
Function: 2/2 way normally closed
Operation: Assisted lift / kick pilot
Electrical operation: Energise to open
The Queen MK40S remains closed when electrically de-energised and opens when power is applied to the solenoid.
Power OFF → Valve CLOSED
Power ON → Valve OPEN
The kick-pilot assisted-lift mechanism provides reliable switching over a wide operating pressure range while allowing the use of a substantially larger main valve orifice than would normally be practical with a conventional direct-acting steam solenoid valve.
Ports & Connections
Port size: 1½" BSPT
Optional connections:
NPT
Rc thread
Orifice: 43mm
Water flow: 257.4 L/min at 1 Bar pressure difference
The large 43mm valve orifice provides excellent flow capacity for industrial steam, water, oil, air and compatible process applications.
Pressure & Performance
Steam pressure: 0 to 10 Bar
Water pressure: 0 to 8 Bar
Oil pressure: 0 to 7 Bar
Orifice: 43mm
Water flow: 257.4 L/min at 1 Bar pressure difference
Maximum media viscosity: 50 cSt
The assisted-lift / kick-pilot design provides a wide operating pressure range and makes the MK40S particularly useful for steam systems where conventional servo-operated valves requiring a significant minimum pressure differential may be unsuitable.
Construction & Materials
Body: BC6 bronze
Internal components: Stainless steel
Seal material: PTFE
The combination of a heavy-duty bronze valve body, stainless steel internals and PTFE sealing provides the durability and temperature resistance required for demanding industrial steam applications.
PTFE High Temperature Sealing
The MK40S uses PTFE sealing to provide reliable operation with high-temperature steam and compatible hot process media.
PTFE provides excellent resistance to elevated temperatures, wear and a wide range of industrial fluids.
Media compatibility should always be confirmed against the bronze body, stainless steel internals and PTFE sealing before use with specialist process fluids.
Suitable Media
Suitable applications include:
✓ Steam
✓ Hot & Cold Water
✓ Hot & Cold Oils
✓ Compressed Air
✓ Vacuum
✓ Inert Gases
✓ Compatible Process Fluids
Maximum media viscosity: 50 cSt
Other gases and process fluids may be suitable where compatible with the materials of construction.
Steam & Temperature Performance
Maximum steam pressure: 10 Bar
Maximum media temperature: +180°C
The high-temperature bronze and PTFE construction makes the MK40S particularly suitable for saturated steam, industrial heating and process applications.
Vacuum & Low Pressure Operation
The kick-pilot assisted-lift design provides operation from very low differential pressure and can also be used for compatible vacuum applications.
This provides an important advantage over conventional pressure-assisted steam valves that rely entirely upon system differential pressure to operate the main valve mechanism.
Installation & Mounting
Recommended mounting position:
Solenoid coil upright
Installation within approximately ±15° of vertical is permitted.
Correct mounting helps ensure reliable operation and long service life of the kick-pilot mechanism.
Coil & Electrical
Solenoid coil: M20
Power: 48VA AC
Insulation: Class H
Duty cycle: 100% continuous duty
Electrical connection: DIN43650A
The high-temperature coil configuration is designed for continuous industrial steam applications.
Voltage Options
AC 50/60Hz:
✓ 110VAC
✓ 230VAC
Select the required operating voltage when ordering.
Normally Closed Fail-Safe Operation
The Queen MK40S provides normally closed fail-safe operation.
With no electrical power applied, the valve remains closed.
When the solenoid is energised, the valve opens and allows flow through the system.
If electrical power is lost, the valve automatically returns to its closed position.
This makes the MK40S suitable for applications where steam, hot water or other process media must automatically shut off following loss of electrical power.
Typical Applications
✓ Industrial Steam Systems
✓ Steam Distribution Systems
✓ Boiler Houses
✓ Process Heating Equipment
✓ Hot Water Systems
✓ Hot Oil Systems
✓ Industrial Autoclaves
✓ Sterilisation Equipment
✓ Food Processing Equipment
✓ Industrial Laundries
✓ Chemical Processing
✓ OEM Machinery
✓ Process Automation
✓ Vacuum Systems
High-Flow Assisted-Lift Design
The Queen MK40S combines a large 43mm flow orifice with assisted-lift kick-pilot operation, providing considerably greater flow capacity than a conventional direct-acting steam solenoid valve.
The kick-pilot mechanism mechanically assists the main valve element during operation, providing reliable switching over a wide pressure range while retaining the flow advantages of a large valve seat.
With water flow up to 257.4 L/min at 1 Bar pressure difference, the MK40S is particularly suitable for larger steam and process pipework requiring high flow and dependable electrical shut-off.
Why Choose the Queen MK40S?
The Queen MK40S provides a robust solution for industrial applications requiring high flow, steam capability and normally closed fail-safe operation.
Its combination of a 43mm orifice, assisted-lift kick-pilot operation, BC6 bronze construction and PTFE sealing makes it particularly suitable for demanding steam, hot water and process applications.
With steam pressure capability up to 10 Bar and media temperatures up to +180°C, the MK40S provides a practical electrically operated solution for larger industrial steam systems.
Ordering Information
Select the required:
Port – 1½" BSPT, NPT or Rc
Voltage – 110VAC or 230VAC
Media and operating pressure
Please contact us for quantity discounts or assistance selecting the correct steam valve configuration.
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