Proving System for Gas Valves Type AD 1 H 1… Type

5.86e
Proving System for Gas Valves
Type AD 1 H 1…
Maximum service pressure 100 mbar
Type
AD 1 H 5…
Maximum service pressure 500 mbar
Features
• Compact unit with a new technology, complete with control valves, programme logic and pressure
sensing system
• Designed according to DIN V 3447, DVGW-approved
• Valve proving requires no opening of same
• Proving times are short and may be set individually to suit different valve sizes
• DVGW-approved for natural gas, propane and manufactured gas
09/02
man_ad1h_586e_0902_uk
Georg Hegwein GmbH & Co. KG · Am Boschwerk 7 · 70469 Stuttgart
Telefon +711 135788-0 · Fax +711 135788-5 · E-mail: [email protected]
AD 1 H ...
Table of Contents
1. Part Numbering System................................................................................................................. 3
2. Technical Data.............................................................................................................................. 3
3. Construction ................................................................................................................................. 4
4. Electrical Connection..................................................................................................................... 5
5. Storage and Operation ................................................................................................................... 6
6. Installation .................................................................................................................................... 6
7. Adjustment ................................................................................................................................... 7
8. Programe Sequence...................................................................................................................... 8
9. Approvals...................................................................................................................................... 9
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1. Part Numbering System
AD 1 H 1, AD1H5
AD 1 H 1 /006, ...H5 /006
Serial device for 100-230 V 50/60 Hz
Serial device for 24 V
(see electrical connenction)
(see electrical connenction)
2. Technical Data
Max operating pressure
AD 1 H 1... ............................100 mbar
AD 1 H 5... ............................500 mbar
Testing pressure
AD 1 H 1... ............................10 - 100 mbar
AD 1 H 5... ............................40 - 400 mbar
Testing time.......................................10 - 100 seconds
Supply voltage
AD 1 H 1 /...H5.........................220/ 230 V AC
100/ 125 V AC
50/ 60 Hz
AD 1 H 1 /006...H5/006 .............24 V DC
Tolerances.........................................220 V
230 V
100 V
125 V
24 V DC
-15%
+10%
-15%
+10%
±20%
Power rating ......................................5 VA
Fuses
S1...........................................4 A Tr.
S2...........................................1 A Tr.
Maximum contact load
terminal 5 - 6............................max. 4 A ohmic
terminal 7 - 8............................max. 1 A ohmic
Terminals ..........................................max. wire size 1.5 mm2
Status indicator (LED)
yellow......................................valve checking running
green.......................................clearance
red ..........................................valve 1 leaking
red ..........................................valve 2 leaking
Mounting position...............................any
Ambient temperature ..........................0°C to +60°C
Protection..........................................lP 54
Insulation class..................................I
Unit base...........................................cast aluminium
Cover ................................................transparent
Weight ..............................................1.5 kg
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3. Construction
The programme logic and the pressure sensor with the control valves is housed underneath a transparent
cover. The pressure sensor system consists of a membrane, 2 microswitches with switching rocker and a
pressure adjustment dome with scale. The programme logic includes the timer and the status indicators
(LEDs).
Panel from top
Housing from top
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Side view
4. Electrical Connection
AD 1 H...
Supply voltage: 220/230 V ~
Note:
•
•
•
Supply voltage: 100/125 V ~
The “valves proved” contact (5+6) should only be wired into the burner management start-up circuit!
The „fault” contact (7+8) should only be used for Remote indication, not as a part of burner safety
logic
A quick blowing 6A fuse has to be installed at site
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AD 1 H... /006
Supply voltage: 24 V DC
Note:
•
•
•
The “valves proved” contact (5+6)
should only be wired into the burner
management start-up circuit!
The „fault” contact (7+8) should only
be used for Remote indication, not as
a part of burner safety logic
A quick blowing 6A fuse has to be
installed at site
5. Storage and Operation
Device are to be stored in a dry and dust-free place. Ambient temperature during storage shall be
0 – 60°C. No operation and storage below dew point. Moisture must not exceed 60%. Device shall be protected from mechanical damages.
The valve proving system checks the tightness of 2 safety shut off gas valves mounted in series. The valve
proving principle is based on pressure changes in the pipe space between the gas valves (the test section)
using the line gas pressure as the test medium which enters or leaves the test section via a restricting
orifice. Thus the restricting orifice determines the test time and limits the volume of gas which is allowed to
enter the furnace chamber at any time.
The built-in timer closes the internal control valves when the adjusted time has elapsed and ends the proving
procedure. The maximum time adjustment for this timer is 100 seconds. A “valves proved” signal will not be
given to the burner management if the time elapses before the valve proving cycle is complete. This must
result in burner lock-out.
Safety related equipment! In case of a break down the unit has to be returned to the manufacturer for inspection.
6. Installation
The valve proving unit and the 2 valves should be installed closely together to keep the test volume small and
thus the testing time as short as possible.The unit can be mounted either on the ¼”-pipe to the test section
or with its fixing straps. Connect the instrument lines “inlet, outlet, test section” as shown. The inlet and
outlet ports are interchangeable if this should be necessary because of the pipework. Loosen the knurled
screws and change the coil of the control valves without disconnecting the wires.
NOTE: In case of back pressure vent the outlet line into atmosphere outside the building!
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7. Adjustment
Adjusting the test pressure
Set the test pressure to 40 % of the dynamic gas pressure. This value must be lower than that of the
minimum gas pressure switch.
Testing procedure
The time required to complete the valve test depends on the following:
a) The volume of the “test section” between the two gas valves.
b) The gas supply test pressure.
c) The adjusted pressure setting and the size of the restricing orifice.
Testing in progress is indicated by the yellow LED being lit.
The internal timer is set at 100 seconds at works. If on site the test proves to be carried out in less than 100
seconds, the timer may be reduced to give say, the actual test time + 5 seconds. This will reduce the valve
check time accordingly.
The unit is fitted at works with a small orifice see table. This orifice diameter ensures that the minimum
leakage rate of the main gas valves as required by DIN will be detected at a maximum operating gas
pressure.
Should the testing time become protracted, because of a large pipe volume (test section), the restrictor bore
may be changed to shorten the test time, subject to the heat release criteria in the DIN standards, as
follows:
AD 1 H 1
built in orifice Ø 0,8 mm
AD 1 H 5
built in orifice Ø 0,6 mm
2 - 5 MW ............................ Ø = 1,2 mm
5 - 10 MW ........................... Ø = 1 mm
larger than 5 MW ................ remove the orifice
(the passage is now
2,0 mm)
larger than 10 MW ............... remove the orifice
(the passage is now 2,0
mm)
Example:
Example:
Test section volume...... 2 Liter
Supply pressure........... 100 mbar
Switching threshold ...... 70 mbar
Test section volume...... 2 Liter
Supply pressure........... 500 mbar
Switching threshold ...... 400 mbar
Resulting testing times:
Resulting testing times:
With orifice Ø 0,8 mm ......... = 20 Sek.
With orifice Ø 1,2 mm ....... = 10 Sek.
Without orifice..................... = 5 Sek.
With orifice Ø 0,6 mm .......... = 35 Sek.
With orifice Ø 1,0 mm ........ = 12 Sek.
Without orifice...................... = 6 Sek.
Note:
Set the valve proving system to a gas pressure considerable lower than that of the pressure switch for the
minimum gas pressure. Otherwise a lower gas pressure could be interpreted as “valve 2 leaking”.
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8. Programe Sequence
- Programme cycle if valves are tight
When energizing the unit the yellow LED will come on. Depending on the pressure status the control valve
“outlet” will be opened. The test section will now be vented via the restrictor into the furnace chamber. This
programme step will be skipped if the test section has been pressureless right from the beginning.
In case of pressureless status the “outlet” valve remains shut, the “inlet” valve opens and pressurizes the
test section. As soon as the pre-adjusted switching threshold pressure has been reached the “inlet” valve
will close. The valve proving is concluded, the yellow LED will go out. As soon as the time limit has clapsed
the “valve proved” contact will be closed and the green LED will come on.
Now the unit is self-maintained. Any pressure drops which might occur when gas valve 2 is opened will
therefore not result in a shut-down
The valve proving system does not act as a pressure switch.
- Programme cycle if leaking of:
Valve 1:
The test section has already been pressurized. Control valve “outlet” opens, however the gas flow venting
through the restrictor is smaller than the gas volume passing through the leaking gas valve.
The presssure in the test section will not fall.
The proving condition for valve 1 cannot be reached. After the elapse of the time limit the “outlet” control valve
closes again, the red LED “valve 1 leaking” comes on and the yellow LED goes out. Remote status
indication is possible through the “fault” contact.
Valve 2 :
The test section is pressureless, the proving condition “valve 1 tight” has been fullfilled. The “inlet” control
valve opens, gas flows through the restrictor into the test section. However there will be no pressure rise
since the gas volume flowing from the test section out through the leaking valve 2 is larger than the volume
fed in. As soon as the time limit elapses the “inlet” valve closes again, the red LED “valve 2 leaking” will
come on, the yellow LED goes out. Remote status indication is possible through the “fault” contact.
Reminder
•
Installation and maintenance procedures may only be carried out by authorized personnel
•
Upon installation, follow local standards and regulations
•
Improper installation or customer side modifications/alterations of the device can cause personal injury or equipment damage
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9. Approvals
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