1.1 The pump consists of two major sub assemblies.

1.2 The crank case sub assembly consists of a CI / Aluminum crank case, in which crank shaft is supported between two ball bearings. Connecting rod connects the cross head / piston to the crank shaft. The cross head / piston is supported by the piston guide which is press fitted in the crank case. Oil seals are provided on the pony rods / pistons as well as either sides of the crank shafts. Coupling unions are located on the crank case, by nuts, which connect the hydraulic sub assembly to the crank case. In some models, studs along with the nuts are used for mounting the hydraulic end on the crank case. Crank case is bolted to the mounting plates called legs. A back cover (normally with cooling fins) is fitted at the back side of the crank case which has a provision for Constant Level Oiler (for Triplex version). A watch glass is provided on the back cover for simplex and duplex versions. A breather plug is fitted on the top of the crank case. The crank case is filled with oil, the level of which is perfectly maintained by CLO.

1.3 The hydraulic sub assembly consists of a suction chamber, a delivery chamber and a valve box which are held together by tie bolts. In some models, single block hydraulic ends are used. Valve seat assemblies along with PTFE sealing washers are fitted inside the hydraulic ports. Some models use valve assemblies with O-rings. Grease nipples provide lubrication to the stuffing box internals.

1.3.1 Standard design of the stuffing box comprises of three gland washers. The lips of these gland washers open out when they are pressurized from outer side by tightening the glad nut. The opened lips, in series, effectively seal the stuffing box.

1.3.2 Gland Washers are supported on a metallic / nonmetallic throat bush called Packing Retainers. Non metallic throat bush is slide fit on the piston / plunger and is designed to restrict the contamination of pumpage as well as loss of lubricant from stuffing box.

1.3.3 A lantern ring / oil ring is provided on the outer side of the packings. It retains the grease in its in built groove which is evenly fed to the stuffing box. The groove has number of holes on its periphery which allow inflow of grease from the grease nipples fitted above the stuffing box. A standard oil ring has a V groove on one side which supports the packing profile. Few models incorporate an oil ring which is flat on not the sides. These models use an additional component called as an Adaptor.

1.3.4 Standard models are provided with Gland nuts on the outer ends of the oil ring which are threaded inside the stuffing box. Gland nut has a round collar with a series of radial holes. These holes provide a seat / location to the wrench which is used for tightening the gland nut.

1.4 Salient Features

1.4.1 Hydraulic chambers are made of heavy duty brass forgings which are Hydro tested to more than double the operating pressure. Some models consist of SS304 machined headers while others use a single block Hydraulic end.

1.4.2 PTFE Washers are used to ensure longer life and effective sealing.

1.4.3 Valve Seat Assemblies are as per international standards (API- 674/ Hydraulic Institute Standard). These are machined within close tolerances and are then ground and lapped in pairs. This ensures excellent sealing and negligible back leakages. A flow tolerance of +2.5 %, can be achieved, which guarantees required Dryness Fraction of the steam, in case of boiler feed application.

1.4.4 Gland washers are made of a specific grade of Neoprene which offers higher wear resistance. These are impregnated with canvas / bolting cloth to enhance the mechanical strength.

1.4.5 Throat bush, made of Grafited PTFE, is used to avoid entry of solid particles (e.g. burs) in the pumpage. It also restricts the grease getting sucked in the Valve Box and thus getting contaminated with the pumpage. (Not in std scope) It offers positive support to the reciprocating piston, thereby avoiding deflections during the to and fro movement. This ensures effective stuffing box sealing and enhanced packing life.

1.4.6 Crank Case is made of high grade CI / Aluminium alloy.

1.4.7 Back Cover is provided with Cooling Fins, to increase radiation losses and to keep the maximum oil bath temperature within safe zone.

1.4.8 Breather Plug is provided instead of conventional oil cap, to avoid chocking of vent holes. It restricts entry of the dust / suspended particles to lube oil. It assures constant ventilation.

1.4.9 Constant Level Oiler automatically maintains the crank case oil at a specified level.

1.4.10 High Tensile Bolts with Lock Washers are used for connecting rods which ensure total safety while running at various loads and temperatures. These are tightened to a specific torque to ensure perfect circularity of big end con-rod bearings.

1.4.11 Standard models use Pistons made of stainless steel and are coated to ensure better wear resistance and longer life of the gland packings.Solid ceramic plungers are used in some models to enhance the operating life.

1.4.12 Pumps parts are epoxy painted / powder coated to take care of the aesthetics.

1.4.13 All the pumps are thoroughly tested as per API standard and the respective findings are recorded in Test Reports which are furnished with the pumps.

1.5 Technical Specifications

• Discharge pressure (max)
• Capacity (max)
• Pump Type
• Temperature (max)
• Speed (max)
• Power
• Suction size
• Discharge size

1.6 Installation of the Pump

1.6.1 Construction (Refer Salient Features)

1.6.2 Main Dimensions, Connections etc can be obtained from the outline drawing.

1.6.3 The location where the pump is installed should be free from vibrations. Anti-vibration mountings are recommended where base plate / platform is prone to vibrations.

1.6.4 In order to protect the pump interiors, covers and plugs of threaded connections should not be removed before the installation of the pump. Foundation should be wiped and cleaned. Proper leveling must be ensured.

1.6.5 Lock Washers should be provided with the bolts used for mounting the pump on base plate / platform.

1.6.6 Before connecting the pump to the driver, the shaft cover should be fitted on the suitable pump side.

1.6.7 Proper alignment of pump and motor pulleys should be ensured. Pulleys must be checked for deflections and run outs if they are any. Use of such pulleys should be strictly avoided.

1.6.8 Proper belt tension must be ensured. Lose / loosened belt causes higher transmission losses (lower rpm and hence lower flow). Excessive tightened belt results in lower belt and bearing life.

1.6.9 Use of proper grade and level of oil should be ensured (Refer Lubrication)

1.6.10 Use of proper grade and quantity of grease should be ensured (Refer Lubrication)

1.6.11 Suction and delivery pipes should be properly selected to avoid leakages

1.6.12 Excessive use of Sealing tapes should be avoided. No sealing tapes should be used on the hydraulic joints.

1.7 Piping Work / Auxiliary Attachments.

1.7.1 Hoses / Pipes should selected with proper pressure ratings and diameters. The transition from small pipe diameters to larger ones should be gradual. (total length of reducer should be 5 to 7 times the normal bore.

1.7.2 Flexible pipes are recommended which are useful in dampening the pulsations resulting in a uniform flow pattern.

1.7.3 In case of rigid piping, undue stresses on the branches / suction and delivery connections should be avoided.

1.7.4 Use of irregular transitions and short bends should be avoided.

1.7.5 Suction and discharge pipes should be checked for twists.

1.7.6 Use of glycerin filled pressure gauges are recommended for longer life. A needle valve should be provided prior to the gauge. This valve should be kept crack open, to dampen the surges, which are likely to damage the gauge.

1.7.7 Relief valve should be set to a proper pressure which will ensure total safety of the pump. Setting pressure should be around 15-20% more than the operating pressure.

1.8 Operation

1.8.1 Start-up

• Check up proper fitment and alignment of pump and motor pulleys. Check up and ensure proper belt tension.
• Check up mounting bolts and ensure the proper and firm fitment of the pump on the base plate / platform.
• Check up suction and discharge pipes for their proper fitment.
• Check and ensure minimum water level in the suction tank.
• Check suction filter for clogging. Clean / replace filter element in case necessary.
• Ensure sufficient amount of grease in grease nipples. Refill the grease cups, in case necessary. Allow small quantity of grease to enter the stuffing box by tightening the grease nipples by two to three rotations.
• It is advisable to thoroughly clean the stuffing box and then install the gland packings in case the pump is not under working condition for a longer period. This can be easily done by removing the complete hydraulic assembly from the crank case by loosening the side coupling unions. (Do not disturb suction and delivery chambers by opening the vertical tie bolts. This may lead to unwarranted replacement of PTFE washers as these act as high pressure sealing gaskets). Replace gland washers if found cracked / worn out.
• Fill up oil in the crank case by using Constant Level Oiler.(Refer Lubrication)
• Ensure, suction valve is in full open condition.
• Switch on the driver and ensure that the pump picks up the speed smoothly. In case of a jerky start, ensure proper belt tension and condition of bearings.

1.8.2 Shut-down

• Stop the driver and ensure that the Rotor comes to a halt smoothly. In case of a jerky halt ensure proper belt tension and condition of the bearings.
• Do not close suction or delivery valve unless the pump comes to a total halt.

1.8.3 Control of Operation

• Reciprocating pump theoretically can develop any amount of pressure irrespective of the basic pump design. The maximum operating pressure in case of such pumps, is the maximum pressure which the pump can mechanically withstand. In other terms, it is the mechanical ability of the pump to withstand the developed pressure. Thus, any amount of pressure within the operating range can be developed by increasing the system resistance (e.g. by throttling the delivery valve or by introducing an orifice in the delivery line.)
• As per the affinity laws, the flow is directly proportional to the speed (rpm). The desired flow can be achieved by running the pump at a particular speed. This speed can be known by calculating exact pulley ratio of the pump and the prime mover. Belt loss (which is about 3 to 5 per cent) should be considered while calculating the net pump speed. Theoretically, a reciprocating pump delivers constant flow, at a particular speed, irrespective of the system head. Practically, a variation in flow to an extent of 2 to 10 percent is observed which is termed as valve loss.
• The operating speed should not exceed the maximum permissible speed indicated on the nameplate. The minimum recommended speed is normally around 15% of the maximum permissible speed.
• The maximum power requirement is the power required for operating the pump at maximum allowable pressure and flow.