Siemens VGG Gas Valves

Siemens VGG gas valves are single-body, threaded gas shut-off valves designed for ON/OFF control in industrial combustion systems. They are commonly specified where a single safety shut-off function is sufficient and are widely used in commercial and industrial burner installations.

VGG valves are designed to be combined with Siemens SKP actuators and are configured as normally closed. Depending on the actuator fitted, they can provide safety shut-off, gas pressure regulation, or air–gas ratio control within the gas train.

Typical Applications

Industrial burners
Boilers and ovens
Gas trains requiring single-stage safety shut-off
Combustion systems using natural gas

Siemens VGG valves are typically selected where threaded pipe connections are required. For installations using flanged connections, Siemens VGF valves may be more appropriate.

Valve Design and Operation

Siemens VGG valves operate exclusively in combination with Siemens SKP actuators. The actuator determines the functional behaviour of the valve within the combustion system.

Depending on the SKP actuator used, a VGG valve may operate as:

ON/OFF safety shut-off valve
Safety shut-off valve with constant pressure regulation
Safety shut-off valve with differential pressure air–gas ratio control
Safety shut-off valve with adjustable air–gas ratio control

This integrated design allows multiple control functions to be achieved using a single valve body, reducing the number of components and fittings required in the gas train. As a result, overall system size and weight can be reduced, and smaller valve diameters may be used.

Compatible Siemens SKP Actuators

SKP15 – Safety shut-off (ON/OFF)
SKP25 – Safety shut-off with constant pressure regulation or zero governor
SKP55 – Safety shut-off with pressure regulation and differential pressure air–gas ratio control
SKP75 – Safety shut-off with pressure regulation and adjustable air–gas ratio control

The actuator can be mounted while the valve is installed and under pressure. SKP regulating actuators are suitable for both low and high supply gas pressure applications.

Available VGG Valve Sizes and Specifications

The table below lists the available Siemens VGG valve models, thread sizes, pressure ratings, flow capacities, and construction materials.

Model Number	Body Style	Size NPT	Maximum Operating Pressure	Close-off Pressure	Capacity CFH Natural gas at P = 1" W.C.	Material
VGG10.154U	Single	1/2" NPT Thread	20 psi	75 psi	327 / 242*	Aluminium
VGG10.204U	Single	3/4" NPT Thread	20 psi	75 psi	614 / 442*	Aluminium
VGG10.254U	Single	1" NPT Thread	20 psi	75 psi	914 / 686*	Aluminium
VGG10.404U	Single	1 1/2" NPT Thread	20 psi	75 psi	2047 / 1643*	Aluminium
VGG10.504U	Single	2"NPT Thread	20 psi	75 psi	3511	Aluminium
VGG10.654U	Single	2 1\2" NPT Thread	10 psi	25 psi	5085	Cast Iron
VGG10.804U	Single	3" NPT Thread	10 psi	25 psi	6158	Cast Iron

Note: VGG valves from 1/2" to 1 1/2" may exhibit reduced flow when used with the AGA66 (NEMA 4) kit. Capacities shown reflect performance with and without the NEMA 4 kit where applicable.

Replacement and Selection Guidance

When replacing an existing Siemens VGG gas valve, the full valve model number shown on the rating plate should always be matched. Valve size, pressure rating, and actuator compatibility must be confirmed to ensure safe and compliant operation.

If you are unsure whether a VGG valve is correct for your application, or if a different valve family is required, technical confirmation is recommended before ordering.

Related Siemens Components

Choose an SKP Actuator

Siemens gas valve bodies require an SKP actuator to operate. The actuator defines the functional behaviour of the valve, including safety shut-off, pressure regulation, and air–gas ratio control. Select the SKP series based on the control function required.