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Series 3G

Series 3G pumps are provided for differential pressures to 250 PSIG (17.2 Bar) and flow rates to 55 GPM (208 L/M).  Mountings include foot or flange.   Casing materials are either cast iron or steel.  These three screw pumps are used for distillate fuel oil transfer and burner services, machinery lubrication and other industrial pumping applications.  Most sizes are available with a tamper resistant built-in pressure relief valve for protection of the pump from momentary pressure overloads.



Nominal flow rate, GPM/LPM, at 200 PSI (14 BAR), 100 SSU (20 CST)
5/18 4/14 - -
6/25 5/18 - -
9/33 7/26 3/11 -
14/52 11/40 5/17 -
18/69 14/54 7/26 5/19
25/94 20/75 10/37 7/27
28/105 22/82 11/40 8/29
34/128 27/101 14/52 10/39
38/144 30/114 15/56 11/42
50/188 40/151 21/78 16/60

Series 3G Specifications

Casing- Cast iron or cast steel.

Rotors- Power rotor is ductile (nodular) iron. Idler rotors are gray iron. Rotors are nitride hardened for use in the 32-60 SSU (2-10 CST) range for fuel oils or for steel cased pumps.

Shaft Seals- Type L: Steel backed Teflon double lip seal for cast iron pumps only, recommended for clean lubricating oil.  Type V: Fluoroelastomer bellows mechanical seal with carbon on niresist faces, fluoroelastomer O-rings, recommended for viscosities below 3000 SSU (650 CST).  Type H: Metal bellows balanced, positive drive mechanical seal with carbon on silicon carbide faces, fluoroelastomer O-rings, recommended for viscosities above 3000 SSU (650 CST) or for closer compliance with API.

Bearing- Internal, ball type.

Relief Valve- Optional internal, tamper resistant, built-in pressure relief valve for viscosities not exceeding 3000 SSU (650 CST). Specify differential set pressure in 15 PSI (1.03 BAR) increments, i.e. 45, 60, 75…255. This relief valve is intended for momentary protection for the pump against overpressure. It is not intended to be a pressure control device. Minimum set pressure is 45 PSID (3.1 BAR). Maximum set pressure is 255 PSID (17.6 BAR).  Steel cased pumps can include an optional built-on, tamper resistant relief valve with external return to tank connection.

Viscosity- 15,000 SSU (3200 CST) maximum except seal type V.

Inlet Pressure- Type L seal 10 PSIG (0.7 BAR).  Types V and H 50 PSIG
(3.4 BAR) maximum

Outlet Pressure- 250 PSIG (17 BAR) maximum [to 300 PSIG (20.7 BAR) with inlet at 50 PSIG (3.4 BAR)]

Temperature- 0 to 225°F (-18 to 107°C)

Drive/Rotation- Direct only. Clockwise rotation facing pump shaft standard. Counterclockwise rotation optional.

Speed- 95 size: 5000 rpm maximum. Sizes 118-162: 4000 rpm maximum.

Mounting- May be foot or flange mounted in any orientation.  Vertical tank mounts available.


Case Material
Iron Steel
Axial, straight thread Standard N/A
Axial, SAE pad Optional Standard
Radial, straight thread Optional N/A
Radial, SAE pad Optional Optional
Radial, straight thread Standard N/A
Radial, SAE pad Optional Standard
Straight thread for use with o-ring fittings. SAE pad is for use with mating SAE 4-bolt 3000 PSI flanges. N/A is not available.

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

Accessories- Completely mounted pump/driver assemblies with baseplates or NEMA ‘C’ face motor adapters are available.

3gcutawy.jpg (13516 bytes)
3G series, 095 casing size with built-in, tamper resistant relief valve, mechanical seal, axial inlet and straight thread ports.

3G Brochure       Drawings