The power rotor is connected directly to the prime mover (electric motor, diesel engine, steam turbine, etc.,) and as it rotates the idlers turn due to the action of the pumped liquid. This action is in effect, that of a piston moving continuously in one direction, providing a smooth uniform flow without pulsations.

The idlers perform no work, so no gears are required to transmit power between the screws. As radial forces on the idlers are taken up by the surrounding cylindrical surfaces, no other bearings are required. Axial forces on the screwset, caused by the pressure differential between inlet and outlet are balanced hydraulically within the pump.

The chamber formed between two adjacent threads and the bore is known as a "closure". It is the closure which contains the liquid as it moves through the pump. As the screwset rotates, the unfolding closures in the suction chamber create low pressure (partial vacuum) areas into which liquid is forced to flow by the pressure differential between this low pressure area, and the absolute pressure on the liquid at the pump inlet. At the discharge end, the folding closures force the liquid into the discharge pipe against the natural resistance (known as discharge pressure) created by the static head and discharge pipe system frictional losses.

The discharge, or back pressure forces a certain portion of liquid to pass back along the internal clearances from discharge to suction. This is a characteristic of all rotary positive displacement pumps. The very fine working clearances of a TRIRO pump reduces this "leakage" or "slip" to a minimum thus maximizing volumetric efficiency.

T-RANGE - Operating Parameters		Pedestal mounted T range pump
Capacity	1.0 to 300 USGPM
Discharge Pressure	up to 300 PSI
Suction Pressure	up to 35 PSI
Viscosity	33 to 8100 SSU
Temperature	-4 to +390°F

This range is designed as a low cost general industrial pump unit for clean liquids. It is constructed in high grade cast iron and features mechanical seal and integral relief valve as standard.

Smaller T range pumps are generally available ex stock with the larger units available on very short lead times.

Free standing horizontal, vertical and tank top mounted units are available, close coupled to electric motors.

API 676 and other specifications

TRIRO J, E and H ranges can be supplied in accordance with the requirements of API 676. Other international pump standards or client specifications can be accommodated.

Turbomechanical Specifications

TRIRO J, E and H ranges can be supplied to meet most turbomechanical specifications and applications including API 614 and API 610 (where relevant to P.D. Pumps).

J-RANGE - Operating Parameters		Flange mounted J range cartridge fitted with anti rotation device to prevent free rotation in reverse.
Capacity	2.6 to 175 USGPM
Discharge Pressure	up to 725 PSI
Suction Pressure	up to 145 PSI
Viscosity	33 to 8100 SSU
Temperature	-4 to +390°F

This range is designed for medium pressure applications on clean liquids. It is produced as a cartridge design. The cartridge has an aluminum alloy construction and features mechanical seal and optional integral relief valve as standard. The cartridge doubles as a renewable sleeve, and can be inserted into a fabricated steel casing to meet the requirements of API specifications. Custom casing designs can be accommodated to meet client dimensions and specifications.

This range can be manufactured in accordance with most oil company and turbomechanical specifications including API 676 / 614 / 610 (were relevant to P.D. pumps).

Horizontal free standing, base mounted, and tank top mounted units are available, close coupled to electric motors.

This range is designed for medium pressure applications on clean liquids. It is produced as a cartridge design. The cartridge has an aluminum alloy construction and features mechanical seal and optional integral relief valve as standard. The cartridge doubles as a renewable sleeve, and can be inserted into a fabricated steel casing to meet the requirements of API specifications. Custom casing designs can be accommodated to meet client dimensions and specifications.

This range can be manufactured in accordance with most oil company and turbomechanical specifications including API 676 / 614 / 610 (were relevant to P.D. pumps).

Horizontal free standing, base mounted, and tank top mounted units are available, close coupled to electric motors.

E-RANGE - Operating Parameters		Sectioned horizontal E range pump
Capacity	175 to 3500 USGPM
Discharge Pressure	up to 725 PSI
Suction Pressure	up to 145 PSI
Viscosity	33 to 8100 SSU
Temperature	-4 to +390°F

This range is designed for medium pressure high flow applications on clean liquids. It is constructed with a renewable sleeve and fabricated steel casing and features mechanical seal and optional integral relief valve as standard. Custom casing designs can be accommodated to meet client dimensions and specifications.

This range can be manufactured in accordance with most oil company and turbomechanical specifications including API 676 / 614 / 610 (were relevant to P.D. pumps).

Horizontal base mounted, vertical free standing, and tank top mounted units are available, close coupled to electric motors.

 Non standard pumps

TRIRO J, E and H ranges can be factory modified for special applications and higher viscosities.

Unitization

Pumps can be supplied bare shaft or assembled with driver in various arrangements including vertical, tank
top, pedestal and base plate options, with spacer or non-spacer couplings and non spark guards.

H-RANGE - Operating Parameters		Base mounted H range pump with Cast Steel casing
Capacity	2.6 to 350 USGPM
Discharge Pressure	up to 2000 PSI
Suction Pressure	up to 145 PSI
Viscosity	33 to 8100 SSU
Temperature	-4 to +390°F
This range is designed for high pressure applications on clean liquids. It is constructed with a renewable sleeve and either cast or fabricated steel casing and features mechanical seal and optional integral relief valve as standard. Custom casing designs can be accommodated to meet client dimensions and specifications. This range can be manufactured in accordance with most oil company and turbomechanical specifications including API 676 / 614 / 610 (where relevant to P.D. pumps). Horizontal base mounted units are available, close coupled to electric motors.