A unit of pressure measurement

Pressure to which the pump will be subjected to for a short duration to insure
casting, seal, and gasket integrity.

Calculating: Hydrostatic test pressures can be to as much as 1.5 times MAWP, but may be
limited by other factors such as the seal. 

A unit of pressure measurement

A unit of pressure measurement

The pressure at which the relief valve begins to open and bypass liquid.

Calculating: This value can be given by the customer or established at 10-15% above the maximum differential pressure for pumps with internal relief valves or the maximum discharge pressure for pumps with return-to-tank valves or in-line system valves.

A unit of pressure measurement equivalent to 100 kilopascals

The rotating assembly in a positive displacement pump, typically driven directly by the motor or other driver.

A unit of torque measurement

A free-rotating part of a rotary positive displacement pump driven by the rotor

A unit of viscosity measurement equivalent to 1 centipoise

A type of gear pump a drive gear featuring inward facing teeth called a rotor. This rotor turns an offset gear with fewer outward facing teeth called an idler. A crescent shape protruding from the head of the pump creates this offset and seals the pumping cavities formed between the gear teeth. Click here to view our How it Works video on this subject. 

A type of gear pump featuring two identical external gears where one gear is the drive gear and one is the driven. The liquid is transferred from between the gear teeth by the rotation of the pump. Click here to view the Pump Report on this subject. 

Any type of rotary positive displacement pump consisting of gears where the pumping results from the unmeshing and remeshing of gears. The liquid is carried between the gear teeth by the rotation of the pump. Common types of gear pumps include internal gear, external gear, and gerotor.

A unit of viscosity measurement equivalent to 1 millimeter squared per second

A type of internal gear pump that is driven by the idler gear and does not include a crescent. Click here to view our How it Works video on this topic. 

A type of rotary positive displacement pump consisting of a pair of externally timed rotors such that each is driven independently and the rotors are non-contacting. Rotor designs vary but some of the more common types include bi-wing (or scimitar), tri-lobe, and various multilobe designs. Similar in operation to a circumferential piston pump. Click here to view our How it Works video on this topic.

A unit of viscosity measurement

A unit of flow measurement (NOTE: slightly different in US and UK units)

A type of kinetic pump consisting of a rotating impeller in a casing volute. This type of pump transfers rotational energy from the spinning impeller to the liquid.

A unit of flow measurement (NOTE: slightly different in US and UK units)

A type of rotary positive displacement pump consisting of a slotted rotor offset in a cam shaped housing. Sliding vanes in the slots of the rotor extend to create pumping cavities, sweep the liquid through the casing, and expel the liquid at the discharge side of the pump as the cam reduces in area and forces each vane back into its slot. Click here to view our How it Works video on this topic. 

A unit of flow measurement

The absolute head required at the inlet of the pump to prevent cavitation, noted with suffix "A" for available from the system or "R" for required by the pump. Similar to NPIP.

A unit of flow measurement

The absolute pressure required at the inlet of the pump to prevent cavitation, noted with suffix "A" for available from the system or "R" for required by the pump. Similar to NPSH.

A unit of flow measurement

Viking Pump’s patented seals which utilize a series of O-rings to create a robust seal and lubrication chamber, all in one. Click here to view the Pump Report on this topic.

A unit of flow measurement

Any pump wherein the seal is located directly behind the rotor, isolating the shaft bushings or bearings from the pumped liquid. An alternative to pumps with seals located in the stuffing box.

Typically consists of braided or formed rings that are compressed in the stuffing box of the pump. As the packing is tightened, it squeezes up against the shaft and the stuffing box wall to create the seal. Click here to view the Pump Report on this topic.

A series of Viking vane pumps named such due to their ability to handle low viscosity liquids even at high pressures.

Consist of two basic parts called faces. One face rotates with the shaft, while a second is held stationary in the pump housing. The primary seal is created between these two seal faces. Click here to view the Pump Report on this topic.

A series of Viking external gear pumps named such due to the cut of the external gears.

Comprised of two independent shafts; one connects to the drive and other connects to the pumping elements. A magnetic coupling transmits the rotation of the drive shaft to the driven shaft inside the pump. Click here to view the Pump Report on this topic.

An older series of Viking external gear pumps which has been largely replaced by the SG Series™

Consists of a flexible elastomeric lip in a rigid housing. The lip seal is stationary and the shaft rotates inside. Click here to view the Pump Report on this topic.

A series of sealless Mag Drive Viking internal gear pumps named such due to their shared dimensions with comparable sized Viking Universal models. Click here to watch the Pump Report related to this subject.

Any seal consisting of one or more elastomeric O-rings. These may be static seals wherein there is no relative motion between parts (i.e. an O-ring seal between a pump casing and bracket) or dynamic seals wherein the seal is created between a moving shaft and a stationary housing (i.e. O-Pro® shaft seals).

A series of sealless Mag Drive Viking external gear pumps named such due to their non-metallic, composite construction.

A mechanical seal or lip seal(s) contained in a preassembled housing to aid in the seal’s installation, maintenance, and replacement.

A series of Viking internal gear pumps constructed to full compliance with API 676 requirements, documentation, and testing.

A special cartridge mechanical seal which has been designed and tested to the American Petroleum Institute’s API 682 standard.

A Viking Pump bracket engineered to accommodate various seal options including O-Pro® Guard seals, single component seals, cartridge lip seals, cartridge single and double mechanical seals. It also includes stainless steel window guards for protection from rotating parts.

Adaptable Viking Pump port design that offers a variety of port sizes and types, enabling flexibility when connecting pumps to piping.

For pumps, this is hollow space where the rotating shaft enters the stationary pump housing. While the term originated from shaft packing that was “stuffed” around the shaft to create a seal, today a pump’s stuffing box is often fitted with a mechanical seal, lip seal, or O-Pro® seal instead of packing.

The maximum allowable difference between the Discharge Pressure and the Inlet Pressure for a given set of operating conditions.
 

Calculating: Provided by the Pump Selector program or Catalog Performance Curves, but may be increased or decreased depending on the application specifics, pump size, and construction. This may be less than or equal to the Full Bypass Pressure of the relief valve. 

A type of pump featuring a pair of opposing diaphragms alternatively expanded by compressed air to expel liquid on the opposite side of the diaphragm. An air valve in the pump shifts the flow of air from one diaphragm to the other resulting in an intake stroke on one side and a discharge stroke on the other. Check valves in the pump prevent the backflow of pumped liquid.

The pressure at which the entire capacity of the pump is bypassing through the relief valve. In other words, this is the maximum differential pressure rating for pumps with internal relief valves or the maximum discharge pressure rating for pumps with return-to-tank valves or in-line system valves.

Calculating: Dependent on the valve used, spring used, and capacity of the pump.

A type of rotary positive displacement pump consisting of a pair of externally timed rotors such that each is driven independently and the rotors are non-contacting. Rotor designs vary but the most common type is bi-wing. Similar in operation to a lobe pump. Click here to view the Pump Report on this subject. 

A unit of viscosity measurement equivalent to 1 millipascal second

A unit of torque measurement

Maximum rated pressure of the pressure containing components of the pump, not including the shaft seal, but including the canister in the case of Mag Drive pumps.

Calculating: MACP can be established as the pressure limit of the port connections for most pump models. In the case of Mag Drive pumps, it can be considered as the hydrostatic limit of the canister divided by 1.5.

The maximum continuous pressure for which the pump is designed.

Calculating: MAWP can be established as the lowest pressure limit of the following 3 components:
1) Shaft Seal
2) Joint Seals
3) Port Connections

The maximum allowable difference between the absolute pressure of the fluid at the inlet port and the absolute ambient pressure.
Calculating: Limited by the same factors as Maximum Allowable Working Pressure (MAWP).

A unit of viscosity measurement equivalent to 1 centistoke

A unit of flow measurement

Pressure at the outlet port of the pump.

Calculating: Discharge pressure is a function of the system and must be calculated or measured. Measurements can be made at the gauge port on the outlet side of the pump or at a point on the outlet pipe as close as possible to the pump.

A mechanical device designed to bypass flow in the result of an overpressure condition at the outlet port of the pump. Click here to view our How it Works video on this topic.

Pressure at the inlet port of the pump. May be positive or negative.

Calculating: Inlet pressure is a function of the system and must be calculated or measured. Measurements can be made at the gauge port on the inlet side of the pump or at a point on the inlet pipe as close as possible to the pump.

A unit of viscosity measurement

The difference between the Discharge Pressure and the Inlet Pressure.
 

Calculating: Differential pressure is a function of the system and must be calculated or measured. Measurements can be made at the gauge ports near the inlet and outlet ports of the pump.