APPLICATION
The VQ400 Series class „A" safety combination valves are
used for control and regulation of gaseous fluids in gas po-
wer burners, atmospheric gas boilers, melting furnaces,
incinerators and other gas consuming appliances.
These combination valves are available in two body sizes:
• model VQ420/25 (pipe sizes 3/4" and 1")
• model VQ440/50 (pipe sizes 1 1/2" and 2")
The 1 1/4" connection is obtained by using a DN32 flange kit
on a VQ440 body.
The features and specifications of both models are identical
(unless specified otherwise).
CLASS „A" COMBINATION VALVES
SPECIFICATION
The specifications described in this chapter are related to
the main gas valve, by-pass valve and pilot valve.
Models
VQ420/25 (DN20 and DN25)
VQ440/50 (DN40 and DN50)
NOTE: DN32 connection is obtained with a flange kit on
Dimensions
See dimensional drawings and table on page 4.
Pipe sizes
Main body: Inlet and outlet straight flange connection 3/4",
Pilot valve and vent valve: outlet 3/4" thread.
(all internal pipe thread according to ISO 7-1)
model VQ440/50
Capacity
Main body: see capacity curves on page 3.
Pilot valve and vent valve on VQ400 DN20 .. 50: as VE4020
By-pass on VQ400 DN20 .. 40:
By-pass on VQ400 DN50
(see capacity curves VE4000 Series product handbook)
Maximum operating pressure
200 or 360 mbar, depending on the model
Opening time
First valve (V1): < 1 sec.
Second valve (V2), by-pass valve and pilot valve:
fast: <1 sec.
slow: adjustable from 1 ... 30 sec.
Vent valve: <1 sec.
Closing time
First valve (V1), second valve (V2), by-pass valve, pilot valve
and vent valve: <1 sec.
Connections
model VQ420/25
•
Pressure taps at inlet and outlet flanges.
•
Optional: 1/4" plug connection for Closed Position
Indication switch (CPI) at bottom of safety valve V1.
At the main body (4) flange connections are provided to
mount either an:
•
internal by-pass valve to achieve high-low flame control
•
internal or external pilot valve
•
vent valve
•
pressure switches (Min. or Max.)
•
Valve Proving System (VPS).
Supply voltages
Line voltage: 220 ... 240 Vac, 50/60 Hz
1
VQ400 Series
INSTRUCTION SHEET
VQ440 body.
1", 1 1/4", 1 1 /2" and 2".
200 Vac, 50/60 Hz
100/110 Vac, 50/60 Hz
24 ... 28 Vdc
MU2C-0042SZ20 R0505
as VE4020
as VE4025