LDU11燃气检漏控制器(SIEMENS) 详细信息
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产品说明：
The LDU11... control detects leakage of the shut-off valves on gas trains with two safety shutoff valves. During each burner cycle, the LDU control unit automatically se, and if a leak is detected, initiates a lockout and prevents the burner from starting up.
Performs leak test of the gas shut-off valves before start-up and/or immediately after burner shut-down
No inlet gas pressure limitations
Easy-to-read dial indicates progress of test program
Ability to eliminate or leak test the vent valve
Cost effective control improves system safety
Globally Approved ?cULus, FM, CE
The LDU11 (or control unit) is used in a gas-fired combustion system with or without a vent valve in the gas train.
Installed with one or two pressure switches mounted between the gas valves, the LDU automatically initiates gas valve proving either
prior to burner start-up
immediately after the controlled shutdown, or
both prior to burner start-up and immediately after shutdown
The valve leak test is completed in two stages:
First test phase Test1, evacuates the pressure between the gas valves to test the upstream gas shutoff valve. The pipe between the gas valves is monitored by a leak detect pressure switch for no increase in pressure.
Second test phase Test2, pressurizes the area between the gas valves to test the downstream safety shutoff valve. The pipe between the gas valves is monitored by the leak detect pressure switch for no decrease in pressure.
If the leak detect switch signals excessive gas pressure increase during the first test phase Test1, or decrease during the second test phase Test2, the LDU control will lockout and prevent burner start-up. The indicator dial on the front of the unit indicates the progress of the leak test. When a fault occurs, the indicator dial stops at the time of lockout, and indicates