Siemens VGD Series, Technical Instructions

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Technical Instructions VGD Series Double Valves
Document Number CC1N7631us
November 08, 2017
Page 2 Siemens AG Building Technologies Division
Features
All Models

UL listed, FM approved, CSA certified, IRI approvable, ISO 9001 and 14000 certified.
CE, Australian approved versions available

¼“ ‐ inch NPT pressure taps on the inlet and outlet and between main valves (see Table 2
for details)

Stainless steel mesh inlet filter protects the valve seat(s) as well as downstream
components

Dual stem guides ensure precise disc alignment and tight shut ‐ off

Valves in connection with SKPxx.xxxU actuators open slowly and close rapidly
VGD20.xxxU models

Compact VGD20.xxxU double ‐ valve bodies consist of 2 safety shut ‐ off valves in series.
The first (inlet) valve has a flat valve disc applicable for safety shut ‐ off function only.
The second (outlet) valve has a contoured valve disc for use with pressure regulating
actuators (SKP2x.xxxU, SKP5x.xxxU, SKP7x.xxxU)

A 1 ‐ inch NPT vent connection between the valves

Each VGD20.xxxU double ‐ valve requires 2 threaded mounting flanges (AGFxx.xxU). Each
flange includes the necessary installation hardware (bolts, nuts and O ‐ ring). Each mounting
flange has a ¼ ‐ inch NPT pressure tap. The flanges can be pre ‐ mounted onto the pipe, and
then bolted onto the VGD20.xxxU gas valve body. This feature eliminates the use of pipe
unions and permits the gas valve assembly to be easily removed from a gas train

Connecting pattern of the 1...2 inch AGFxx.xxU flanges are identical. This space permits
any AGFxx.xxU flange to be mounted to any VGD20.xxxU valve body

NOTE:
VGD20.xxxU valves and AGFxx.xxU flanges must be ordered as separate items (see
Tables 2 and 3 ).
VGD40.xxxU models

Compact VGD40.xxxU double ‐ valve bodies consist of 2 safety shut ‐ off valves in series

Each individual safety shut ‐ off valve has double seats to achieve high flow

Patented seat construction with individual closing spring for each seat to assure reliable
shut ‐ off and high close ‐ off pressure rating

Full port vent line connection plates are available

NOTE:
VGD40.xxxU valves and AGA40.xxxxU vent connection plates must be ordered as
separate items (see Tables 2 and 3 ).