Siemens Actuator SKP55 Series

Siemens SKP55 Series electrohydraulic actuators combine gas valve operation with an integrated differential pressure governor. The governor maintains a fixed 1:1 relationship between gas and combustion air differential pressures throughout the operating range. Featuring controlled valve opening and rapid shutoff, the SKP55 is designed for compatible Siemens gas valves in industrial burner systems, boilers and gas-fired combustion equipment.

Product Description

Siemens SKP55 Series Differential Pressure Gas Valve Actuators

Siemens SKP55 Series actuators integrate electrohydraulic gas valve operation with differential pressure regulation. Designed for industrial combustion equipment, they control gas differential pressure in response to combustion air differential pressure, maintaining a consistent 1:1 relationship across the operating air range.

When fitted to compatible Siemens VGx/VRx gas valves, the SKP55 supports gas safety shutoff and differential pressure control. Its electrohydraulic mechanism provides damped valve opening and rapid closure when electrical power is interrupted.

Key Features

  • Integrated differential pressure governor maintains a fixed 1:1 gas-to-air differential pressure ratio
  • Electrohydraulic mechanism for gas valve actuation
  • Controlled, damped opening and valve closure in less than 1 second during shutdown
  • AC 120 V and AC 230 V supply variants, depending on model
  • Maximum power demand of 10 VA for European versions
  • Available with or without an end switch for closed-position indication
  • Compatible with gas families I–III when used with suitable valves
  • IP54 protection, with IP65 achievable using the AGA66 accessory under specified installation conditions

Industrial Applications

Siemens SKP55 actuators are suitable for gas combustion equipment that requires differential gas pressure to follow combustion air differential pressure. Common applications include:

  • Industrial gas-fired burner installations
  • Industrial boiler systems
  • Combustion plants incorporating heat recovery equipment
  • Burner installations with varying combustion chamber or burner pressures
  • Burners equipped with adjustable air and fuel mixing devices
  • Systems with negative pressure on the gas side or combustion air side

Siemens SKP55 Model Variants

  • SKP55.001E1 – AC 120 V, with end switch
  • SKP55.001E2 – AC 230 V, with end switch
  • SKP55.003E1 – AC 120 V, without end switch
  • SKP55.003E2 – AC 230 V, without end switch

Selection Note: Check the complete actuator designation, electrical supply, compatible gas valve and mounting requirements before ordering. Installation and governor adjustments must be carried out by qualified combustion system technicians.

Specifications

Siemens SKP55 Actuators – Technical Data and Specifications

ManufacturerSiemens
Actuator SeriesSKP55 Series
Equipment ClassificationElectrohydraulic Gas Valve Actuator
Integrated GovernorDifferential Pressure Governor
Rated Supply VoltagesAC 120 V (-15%/+10%)
AC 230 V (-15%/+10%)
Supply Frequency50/60 Hz ±6%
Maximum Power Requirement10 VA
Valve Shutoff Response<1 second at shutdown
Typical Valve Opening RateApproximately 2 mm/s
Gas-to-Air Differential Pressure Ratio1:1
Regulated Gas Differential Pressure0.03–20 kPa
Reference Combustion Air Differential Pressure0.03–20 kPa
Maximum Allowable Operating Pressure120 kPa
Parallel Gas Pressure Offset Adjustment±0.1 kPa
Pressure Regulation Accuracy<10% at Δpmin
<1% at Δpmax
Ingress ProtectionIP54
IP65 with AGA66 accessory, subject to installation requirements
Electrical Safety ClassificationClass I
Operating Ambient Temperature-10 to +60 °C
-20 to +60 °C with AGA63.5A27 heating element
Permissible Relative Humidity<95% RH
Approximate Device Weight1.9 kg
Supported Gas FamiliesI–III
End Switch OptionsWith or without an end switch, depending on model
Reference StandardsEN 161, DIN EN 88-1

Technical Reference: Specifications are drawn from Siemens Technical Data Sheet CC1N7643en, dated 06.04.2022. Individual characteristics may vary according to the selected valve, installed accessories and operating conditions.