SANDPIPER GH2 User Manual
SERVICE AND OPERATING MANUAL
Model GH2
High Pressure
1:2 ratio Type 1
Designed to meet CSA Requirement 2:01 US for Natural Gas Operated Diaphragm Pumps
PRINCIPLE OF OPERATION
This pump is a 2:1 pressure ratio single acting pump powered by compressed
natural gas. The 2:1 ratio is achieved by simultaneously applying gas pressure
over a single end of each of two pistons connected in series by a shaft. The two
pressurized ends are those most distant from the pumped fluid, with the force from
the gas pressure exerted in the direction of the pumped fluid. The combined force is
transferred through to the single end of the piston nearer to the pumped fluid—the
single piston end having an area equal to one-half that of the two “gas” ends—and
then through a fluid cell to a single pumping diaphragm.
On this single acting pump the suction stroke is independent of all discharge
conditions and requires less gas pressure than the discharge stroke. The suction stroke is accomplished through a natural gas regulator which pressurizes the piston area in the rear cylinder adjacent to the intermediate bracket, while
simultaneously exhausting the other two piston areas: one in the front cylinder, adjacent
to the intermediate bracket, and the other behind the rear cylinder piston, adjacent to
the cap end.
OPERATION
The regulator is factory preset to 30 psi. After the pump is installed and in
operation, the operator should raise or lower the setting until maximum
performance is determined by trial and error. A setting which is too high will result
in excessively rapid and noisy operation, with a loss in performance and eventually
shortened pump life.
The hose assemblies deliver natural gas to the non-wetted portions of the pump,
and care should be taken that they are neither crimped nor cut.
INSTALLATION PROCEDURES
Position the pump as close as possible to the source of the liquid to be pumped.
Avoid long or undersize suction lines and use the minimum number of fittings.
For permanent installation involving rigid piping, install short flexible sections
of hose between the pump and piping. This reduces strains and permits easier
removal of the pump for service when required. Important: The pump must be
installed on a flat, level surface. Use shims as neccessary.
NATURAL GAS SUPPLY
Do not connect the unit to a natural gas supply in excess of 125 PSI (8.61
bars). Install a shutoff valve in the gas supply line to permit removal of the unit for
servicing. When connecting a gas supply of rigid piping, mount a section of flexible
line to the pump to eliminate piping strain. In permanent installations, a gas filter is
recommended.
FREEZING OR ICING OF EXHAUST
Icing of the gas exhaust can occur under certain conditions of temperature and
humidity on compressed gas power equipment. Icing is more likely to occur at high
discharge pressures.
MAINTENANCE AFTER USE
When the pump is used for materials that tend to settle out or transform from liquid
to solid form, care must be taken after each use or during idle time to remove them
and flush the pump as required to prevent damage. In freezing temperatures the pump
must be completely drained when idle. This model must be tilted to allow the liquid from
the chambers to run out of the discharge port.
IMPORTANT
Read these safety
warnings and
instructions in this
manual completely,
before installation and start-up of the pump.
It is the responsibility of the purchaser to
retain this manual for reference. Failure to
comply with the recommendations stated
in this manual will damage the pump, and
void factory warranty.
CAUTION
Before pump
operation, inspect all
gasketed fasteners
for looseness caused
by gasket creep. Retorque loose fasteners to prevent leakage.
Follow recommended torques stated in
this manual.
WARNING
Before maintenance
or repair, shut off the
com-pressed air line,
bleed the pressure,
and disconnect the
air line from the pump.
The discharge line may be pressurized
and must be bled of its pressure.
WARNING
In the event of
diaphragm rupture,
pumped material may
enter the air end of
the pump, and be
discharged into the atmosphere. The air
exhaust must be piped to an appropriate
area for safe disposition.
WARNING
Take action to prevent
static sparking. Fire
or explosion can
result, especially
when handling
flammable liquids.
The pump, piping, valves,
containers or other miscellaneous
equipment must be grounded.
WARREN RUPP®, IDEX AODD, Inc. • A Unit of IDEX Corporation • 800 N. Main St., P.O. Box 1568, Mansfield, Ohio 44901-1568 USA
Telephone (419) 524-8388 • Fax (419) 522-7867 • www.warrenrupp.com
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CHECK VALVE SERVICING
Need for inspection or service is usually indicated by poor priming, unstable cycling,
reduced performance or the pump’s cycling but not pumping.
DIAPHRAGM SERVICING/FILLING DRIVER FLUID
Motive power is delivered to the single diaphragm of the pump through a
fluid cell located between the diaphragm and the drive piston. During preventative
maintenance servicing (where the diaphragm has not ruptured, and the fluid cell is still
filled), the fluid should be drained from the chamber by removing the pipe plug, in the
lower most portion of inner chamber, item 54.
To fill the fluid cell, the piston(s) must be on full discharge stroke. To do this and hold
during fill procedure, remove item 46, (fitting) from the cylinder cap (item 15) and insert
gas pressure. This need not be more than 10 PSI. This will move the piston(s) and hold
them in the discharge position. Remove the pipe plug at the top of the fluid chamber,
and fill the chamber with ethylene glycol (anti-freeze). The chamber will take 3000 ml
(101.5 fluid ounces) of fluid. If the diaphragm is PTFE, use 2800 ml (95 fluid ounces).
Tilt the pump to evacuate air pockets from the fluid chamber. A box wrench can be used
to flex the diaphragm and purge air from the fluid chamber. Fill the chamber to the top
of the fill hole, and re-insert the pipe plug, using thread compound.
If the glycol cell fluid is not compatible with the pumped product or would form a
potentially dangerous mixture if the diaphragm ruptured, consult the factory before
choosing an alternative fluid.
CYLINDER PISTON SERVICING
The driver fluid must be drained (see above) to service the cylinder piston.
The piston seals are different on the natural gas side versus the driver fluid side.
Typically, the fluid side will require replacement before the gas side. Remove the nuts
and washers that secure the gas side piston cap and inner fluid chamber to the intermediate bracket. The cylinders may now be removed. Inspect the cylinder wall carefully.
Scratches can cause driver fluid to leak to the gas side of the pump, which can find
its way to the exhaust muffler. Scratches on the gas cylinder will cause too much gas
to leak when on pressure stroke. The locknuts holding the cylinder to the rod can now
be removed. Carefully inspect the piston for scratches, burrs and wear, especially if
the piston seals are worn.
The piston seals can now be inspected or replaced. NATURAL GAS SIDE–The
gas side piston has a T-Seal. If the seal is worn showing flat areas or gouges, it
will require replacement. Remove seal and back-up (spacer). Remove wear rings
and carefully inspect for wear. During reassembly make sure the ends of the back
up spacer and wear ring end are not across from each other. WET SIDE–The wet
side piston has a yellow PSP seal. Inspect for flat spots and gouges. Behind the
seal is an energizer ring that helps to load the seal against the cylinder wall. (The
energizer ring is included with the new seal.) The wear rings are the same as on the
air side. Again, make sure the ends are not across from each other.
Reassembly of both pistons is the opposite of removal. Make sure the side of the
locknut with the seal is next to the piston. The groove in the piston or o-ring (item
35), must be toward the pump center (o-ring seals next to the rod). Apply a heavy oil to
the piston seals when sliding on the cylinder. The piston/nut should be torqued at 500
in./lbs. (56.49 Newton meters). The studs that secure the cylinders to the intermediate
should be torqued at 250 in./lbs. (28.24 Newton meters). IMPORTANT NOTE: Reas-
sembly of the wet side piston/seal assembly differs from the gas side in that it must be
carefully pressed into the cylinder. An arbor press is commonly used for this purpose.
WARNING
Do not smoke near
the pump or use
the pump near an
open flame. Fire or
explosion could result.
WARNING
This pump must not
be used for fluid
transfer into aircraft.
WARNING
This pump is
pressurized internally
with natural gas
pressure during
operation. Always
make certain that all bolting is in good
condition and that all of the correct bolting
is reinstalled during assembly.
WARNING
When used for toxic or
aggressive fluids, the
pump should always
be flushed clean prior
to disassembly.
WARNING
Before doing any
main-tenance on the
pump, be certain
all pressure is
completely vented
from the pump, suction, discharge, piping,
and all other openings and connections.
Be certain the natural gas supply is locked
out or made non-operational, so that it
cannot be started while work is being done
on the pump. Be certain that approved
eye protection and protective clothing are
worn all times in the vicinity of the pump.
Failure to follow these recommendations
may result in serious injury or death.
WARNING
Airborne particles and
loud noise hazards.
Wear ear and eye
protection.
NATURAL GAS VALVE LUBRICATION
The SandPIPER pump’s pilot valve and main gas valve assemblies are
designed to operate WITHOUT lubrication. This is the preferred mode of operation.
There may be instances of personal preference, or poor quality gas supplies when
lubrication of the compressed natural gas supply is required. The pump gas system
will operate with properly lubricated compressed gas supplies. Proper lubricatrion
of the compressed gas supply would entail the use of a natural gas line lubricator
set to deliver one drop of 10 wt., non-detergent oil for every 20 SCFM of gas
the pump consumed at its point of operation. Consult the pump’s published
performance curve to determine this.
It is important to remember to inspect the sleeve and spool set routinely. It should
Model GH2 Page 2 gh2dl1sm-REV0714
Pump complies with EN809 Pumping
Directive, Directive 98/37/EC Safety of
Machinery.
move back and forth freely. This is most important when the gas supply is lubricated.
If a lubricator is used, oil accumulation will, over time, collect any debris from the compressed gas. This can prevent the pump from operating properly.
Water in the compressed gas supply can create problems such as icing or
freezing of the exhaust gas causing the pump to cycle erratically, or stop operating.
This can be addressed by using a point of use dryer to supplement a plant’s gas drying
equipment. This device will remove excess water from the compressed gas supply and
alleviate the icing or freezing problem.
ESGDS: Externally Serviceable Gas Distribution System
Please refer to the exploded view drawing and parts list in the Service Manual
supplied with your pump. If you need replacement or additional copies, contact your
local Warren Rupp Distributor, or the Warren Rupp factory Literature Department. To
receive the correct manual, you must specify the MODEL and TYPE information found
on the name plate of the pump.
Main Natural Gas Valve
The main natural gas valve sleeve and spool set is located in the valve body mounted
on the pump with four hex head capscrews. The valve body assembly is removed from
the pump by removing these four hex head capscrews.
With the valve body assembly off the pump, access to the sleeve and spool set is
made by removing four hex head capscrews (each end) on the end caps of the valve
body assembly. With the end caps removed, slide the spool back and forth in the sleeve.
The spool is closely sized to the sleeve and must move freely to allow for proper pump
operation. An accumulation of oil, dirt or other contaminants from the pump’s gas supply, or from a failed diaphragm, may prevent the spool from moving freely. This can
cause the spool to stick in a position that prevents the pump from operating. If this is
the case, the sleeve and spool set should be removed from the valve body for cleaning
and further inspection.
Remove the spool from the sleeve. Using an arbor press or bench vise (with
an improvised mandrel), press the sleeve from the valve body. Take care not to
damage the sleeve. At this point, inspect the o-rings on the sleeve for nicks, tears or
abrasions. Damage of this sort could happen during assembly or servicing. A sheared
or cut o-ring can allow the pump’s compressed gas supply to leak or bypass within the
valve assembly, causing the pump to leak compressed gas from the pump exhaust
or not cycle properly. This is most noticeable at pump dead head or high discharge
pressure conditions. Replace any of these o-rings as required or set up a routine,
preventive maintenance schedule to do so on a regular basis. This practice should
include cleaning the spool and sleeve components with a safety solvent or equivalent,
inspecting for signs of wear or damage, and replacing worn components.
To re-install the sleeve and spool set, lightly lubricate the o-rings on the
sleeve with an o-ring assembly lubricant or lightweight oil (such as 10 wt. gas line
lubricant). Press the set into the valve body easily, without shearing the o-rings.
Re-install one end cap, gasket and bumper on the valve body. Using the arbor press or
bench vise that was used in disassembly, press the sleeve back into the valve body. You
may have to clean the surfaces of the valve body where the end caps mount. Material
may remain from the old gasket. Old material not cleaned from this area may cause air
leakage after reassembly. Take care that the bumper stays in place allowing the sleeve
to press in all the way. Reinstall the spool, the opposite end cap, gasket and bumper
on the valve body. After inspecting and cleaning the gasket surfaces on the valve body
and intermediate, reinstall the valve body on the pump using new gaskets. Tighten the
four hex head capscrews evenly and in an alternating cross pattern.
PILOT VALVE ACTUATOR SERVICING
The bushings for the pilot valve actuators are threaded into the intermediate bracket from the outside. The plunger may be removed for inspection or
replacement from the inside by removing the natural gas distribution valve body and
the pilot valve body from the pump. The plungers should be visible as you look into
the intermediate from the top. Depending on their position, you may find it necessary
to use a fine piece of wire to pull them out.
Under rare circumstances, it may become necessary to replace the o-ring seal. The
bushing can be pushed through the inner chamber by removing the outer chamber the
assembly to reach the bushing.
TROUBLE SHOOTING
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