Series 4U/4T

The 4U series pump is intended primarily as a medium pressure fluid power pump.   It is available foot or flange mounted and is suitable for cyclic pressure service.  

The 4T series is produced in a cast steel casing with a combined foot/flange mounting arrangement.  The pump is primarily used for medium pressure gas sealing applications on compressors.

Series 4U/4T Specifications

Casing-   4T: Cast alloy steel. 4U: High tensile, close grain cast iron

Rotor Housing-   Pearlitic gray iron

Power Rotor-   Alloy steel, hardened and thread ground.

Idler Rotors-   Alloy steel or pearlitic cast iron, hardened and thread ground.

Gaskets-  Cellulose and non-asbestos fiber.

Seal & Bearing-  Fluoroelastomer bellows mechanical seal with carbon on niresist faces and an external, permanently grease packed, deep groove ball bearing. Carbon on carbide seal faces available on 4T series.

Accessories-   Completely mounted, built to order pump/driver assemblies are available with baseplates, etc.

Outlet Pressure-   1500 PSIG (103.4 BAR) maximum. 2000 PSIG (138 BAR) under certain conditions. Consult Imo Pump.  Minimum recommended differential pressure is 50 PSIG (3.4 BAR).

Inlet Pressure-   4T: 75 PSIG (5.2 BAR) maximum, sizes 137 & 156. All others, 50 PSIG (3.4 BAR) maximum. 4U: 50 PSIG (3.4 BAR) maximum.

Viscosity-  60 to 3000 SSU (10 to 650 CST). Hydraulic oils, lube oils, phosphate ester and water-glycol fire resistant fluids can be handled per standard pump ratings.

Temperature-  0 to 180°F (-18 to 82°C).

Drive-  Direct only.

Rotation-  Clockwise facing pump shaft. Counterclockwise rotation optional.

Mounting-   May be foot or flange mounted in any attitude.

Filtration-   Inlet strainers are required to keep contaminants and abrasives out of the pump. They must be selected in consultation with the strainer vendor to prevent pump starvation. Normally, 60 mesh (0.01 inch- 238micron) for light and 1/8-3/16 inch (3-5mm) openings for heavy oils are recommended.

Connections-  Inlets and outlets are SAE 4-bolt flange pads. Mating socket weld flanges are included with 4T series pumps but must be specified and purchased separately for 4U series pumps. All 4T inlet heads are rotatable in 90° increments. Series 4U inlet heads are rotatable in the following increments: Sizes 137 & 156: 60°.  Sizes 187 & UP: 45°. SAE port pad bolt patterns are for 3000 PSI rated flanges except  the 218/250 casing sizes use a 500 PSI pattern on the inlet and 187/200 outlet  uses a 6000 PSI pattern.

Maximum Speed*-  Sizes 137 & 156: 4400 RPM. Sizes 187 & UP: 3600 RPM. Special pumps available to 8000 RPM with boosted inlet pressure. Consult Imo Pump.

* Assumes minimum inlet pressure requirements are met.

Typical cutaway for the 4UVC and 6UVC Series.  A 6U is shown; the 4U is shorter having fewer screw wraps. 
The 4T and 6T are very similar but have a combined flange/foot mounting arrangement as well as a steel casing.