What are gear pumps used for?

The pumping of high viscosity lubricating fluids such as oils, fuels, paints, soaps and resins. The pumping of low viscosity fluids should be avoided as they can cause fluid to leak backwards or "slip" back to the suction side.

What is an external gear pump?

An external gear pump has two identical gears positioned side by side, rotating and interlocking into one another. One is driven by the motor and in turn moves the other gear.

Difference between internal gear pump and external gear pump?

Whilst external gear pumps offer higher pressure and flow rates, internal gear pumps generally have better suction capabilities and are able to handle higher temperature, higher viscosity fluids. Internal gear pumps slower speeds and larger clearances also makes them more suitable for shear sensitive fluids

Are gear pumps self priming?

Yes. Gear pumps have excellent self-priming capabilities thanks to their rotating gears evacuating any air in the suction line, and forcing the liquid into the pump inlet.

Are gear pumps able to handle solids?

The close tolerances between the gears and casing mean that pumping solids will result in wear and damage. Some internal gear pump designs which have less tight tolerances and slower speeds however may be able to tolerate small solids.

Need help choosing the right pump or technical advice? Call the team on 01773 533 283.

Yildiz YHL External Helical Gear Pump

Resin Pump & Thermal Oil Pump

Key Specifications
Max Flow Rate	5833lpm
Max Head	150M
Max Temperature	350°C
Max Viscosity	250, 000 cP
Solids	0mm
Sizes	2" to 10"

Datasheet

Enquire now about this product

This Helical Gear Pump range is designed for pumping low to high viscosity fluids with lubricating properties at high temperatures. There is also the option for these external gear pumps to be supplied with an external heating jacket to maintain the temperature of the pumped medium. Due to the tight clearance between the gears, these helical external gear pumps are not designed for fluids containing abrasive particles. The most common applications include fuel oil transfer, diesel fuel transfer, coolant transfer, OEM, hot oil circulation, food industry, marine, and lubrication.

Features of the Yildiz YHL gear pump:

Helical external gear pump
Designed for medium pressure, high temperature applications
Compact design
Various material options
Various sealing options
Pressure relief valve on cover
External jacket cover to maintain liquid temperature available
230v, three phase 50/60hz motors available
Motor and gearbox drive available
Manufactured according to CE regulations
Explosion proof ATEX rated motors and non-sparking flexible couplings are available

Read our gear pump guide for detailed information on how they operate and the applications they are commonly used for.

	CAST IRON	STEEL CAST	STAINLESS AISI 304/316 CAST	SNBZ 12 BRONZE	BEARING	CARBON GRAPHITE	INA BUSHING BEARING	SOFT SEAL	MECHANICAL SEAL
PUMP BODY & COVERS	X	X	X
GEARS	X	X	X
BEARINGS				X	X	X	X
SEALING								X	X

YHL Helical Gear Pump Datasheet

FAQs

Gear pumps operate by an unchanging volume of fluid passing between the teeth of two meshing gears and their casing at a constant rate (not between the gears themselves). As the gears rotate and the meshed teeth separate, a partial vacuum is formed that fills with fluid, which they trap and move it around the casing from the suction to the discharge point.