9
FOR LIQUID GASES SERVICE (FIG.13)
START-UP
Recommendedfor use withCO, Butane, Propane,Freon, and other
liquified gases warmer than–150°F (–101°C). Meter may be
mounted above or below tank.
Vapour generator is a 12" length of 1" to 1½" diameter pipe; avoid
traps or pockets between vapour generator and tank. Install inverted
“U” gas trap inside tank. Do not insulate piping below lower shutoff
valve. Do not share fill or vapor return lines with meter piping.
1. Close block valves.
2. Open drain valve and loosen meter housing drain plugs to remove
all liquid from system. Replace plugs.
3. Close drain valve and slowly open bottom shutoff valve to allow
liquid to enter gas generator.
4. Open upper shutoff valve and block valves.
FOR CRYOGENIC LIQUID SERVICE (FIG.14)
START-UP
Recommended for use with Oxygen, Nitrogen, and Agron.
Instrument may be mounted above or below tank. Vapour
generator is a spiral of 3/8" turbing. Install an inverted “U” gas
trap inside tank. Do not share fill and vapour return lines with
meter piping.
CAUTION : Instrument designed for use with Oxygen are specially
cleaned and packaged, and MUST be kept clean. No organic
compounds, oil, grease, dirt, or scale of any kind can be tolerated in
an oxygen installation.
1. Close block valves. Loosen instrument body drain plugs to
remove all liquid from system. Replace Plugs.
2. Slowly open HP (bottom) shutoff valve to allow liquid to flow
through gas generator.
3. Open LP (top) shutoff valve, and open block valves.
L FINALADJUSTMENT
It is advisable to recheck instrument zero and to test the operation of the bypass valve after the D.P. Gauge has been
placed inservice and fully subjected to differential pressure, line pressure, and process/ambient temperature.
CAUTION : Never zero check when only one block valve is shut. In gas flow service, a standing wave effect in the
process line can displace the indicator; the displacement could be assumed to be an erroneous reading.
1. With the instrument subjected to differential pressure and in service, observe the position of the pointer on the
scale and use this reading as a reference for checking the effectiveness of the bypass valve on the instrument
piping manifold. Close the H.P block valve. (Note that when checking instrument zero where seal pots are involved,
the primary element shutoff valve is used instead of the meter body valve on the piping manifold). If the pointer
moves from the reference position towards zero, it indicates that the bypass valve on the piping manifold is leaking and
must be replaced. If the pointer remains in the reference position, the bypass valve is functioning properly.
2. Open the bypass valve on the instrument piping manifold. The pointer should go to zero on the scale. If the
instrument does not indicate zero, check for gas or liquid entrapment in the lines or in the D.P. Gauge (depending
on the orientation of the piping layout and service). If necessary, adjust the pointer by turning the dial to bring the
pointer to zero reference.
3. Adjustment of the Pulsation Dampener
CAUTION : Never try to remove the pulsation dampener adjusting screw. Serious injury can result if adjustment screw
is removed with the instrument under pressure. When an increase in dampening is required, as indicated by a quivering
movement of the instrument pointer, turn the damping screw clockwise until the pointer just stops its oscillation. Do
not over-adjust. (See “Operating Limitations-Pulsation” explained earlier). Further damping will decrease the speed
of response and introduce unnecessary time lag into the measuring system. Recheck instrument zero.
