Algas SDI Direct Fired 120/60H, Operation & Maintenance Manual

Page: 17 / 56

Installation
Algas-SDI Operation and Maintenance Manual
– P/N – 52642
2-7
1. Install a UL listed shut-off valve with a minimum 250 psig (17.24 bar) gas
pressure rating.
2. Install a 0-300 psig (0-20.7 bar) pressure gauge (or provisions for one) ahead
of the 1 st stage regulator.
3. Install the first stage regulator as close to the vaporizer as possible, but not
further than 24” (0.6 m) from the outlet of the vaporizer. The outlet pressure
of the regulator should be set at 4 to 6 psig (0.3 to 0.4 bar) lower than tank
saturated vapor pressure at lowest expected temperature; this may require
periodic adjustment.
4. The second stage (or low pressure) regulator should be installed as close to
the consuming equipment as practical.
5. A line relief valve may be installed (optional) to protect the regulators from
excessively high pressure. If a line relief valve is used, set the blow pressure
at approximately 10 PSI (0.7 bar) above the first stage regulator delivery
pressure.
LIQUID INLET
NOTE
Do not install a check valve in the supply line between the tank and
the vaporizer. Liquid must be able to flow both ways in that line.
1. Install the 60-mesh 3/4" strainer that is supplied with the unit on the liquid
inlet to the vaporizer.
2. Install a UL listed shut-off valve with a minimum 250 psig (17.24 bar) gas
pressure rating.
3. Install a 0-300 psig (0-20.7 bar) pressure gauge (or provisions for one) ahead
of the liquid inlet valve.
4. The liquid line from the storage tank to the vaporizer should be of sufficient
size to supply the vaporizer at full capacity with a maximum pressure drop of
less than the hydrostatic head pressure (
see NFPA 54 ).
5. Connect the vaporizer to the storage tank.
VAPOR BYPASS LINE - see Figure 3
1. Install a primary (first stage) regulator at the vapor outlet on top of the
storage tank. Set this regulator to deliver gas at a pressure of 2 to 4 psig
(0.14 to 0.3 bar) below the setting of the vaporizer regulator. Then, if the
vaporizer is overloaded or its output pressure drops off, the regulator on top
of the storage tank will automatically take over.
2. Run a line from the regulator and tie it into the vapor service line downstream
of the vaporizer first stage regulator.
3. Although vapor bypass line is not required for proper operation, it is
recommended for all installations.