Cooling Systems - Engine Flushing Systems

1/2" Water Pressure Dump
Your Price:
$115.99

1/2" Stainless Steel In Line Pressure Relief Valve Water Dump

128-5015

This has to be one of the coolest and simplest stream lined inventions to come along in recent times. High water pressure spikes plague numerous boats and cause catastrophic engine damage. Until now your only option was an independent pressure relief valve that you then had to plumb to a water dump to discharge the water. Thanks to the Hardin Marine team they have taken the best high flow water valve design and integrated it into a common water dump.

These dumps feature a sleek design as well as unique wrench flats machined into the body aiding in assembly during a one person installation. Constructed from 316L stainless steel. This model provides a 1/2 NPT female thread allowing for any arrangement of possible fitting and hose connections. The unit features a stainless tulip style valve that is spring loaded. The units come preset at approximately 10psi.

  • 1-7/16" Flange Diameter
  • 1/4" Flange Height 
  • 1-1/8" Shaft Outside Diameter
  • 3" Overall Length
  • 1/2" NPT Internal Thread
  • Pre-set at Aprox. 10lb Pressure Relief 
  • Approx. Flow Rate (gallons per minute) 10 psi=7 GPM, 15 psi= 13 GPM, 20 psi=19 GPM

1/2" Water Pressure Dump
Your Price:
$115.99

3/4" Stainless Steel In Line Pressure Relief Valve Water Dump

128-5016

This has to be one of the coolest and simplest stream lined inventions to come along in recent times. High water pressure spikes plague numerous boats and cause catastrophic engine damage. Until now your only option was an independent pressure relief valve that you then had to plumb to a water dump to discharge the water. Thanks to the Hardin Marine team they have taken the best high flow water valve design and integrated it into a common water dump.

These dumps feature a sleek design as well as unique wrench flats machined into the body aiding in assembly during a one person installation. Constructed from 316L stainless steel. This model provides a 3/4 NPT female thread allowing for any arrangement of possible fitting and hose connections. The unit features a stainless tulip style valve that is spring loaded. The units come preset at approximately 10psi.

  • 1-3/4" Flange Diameter
  • 1/4" Flange Height 
  • 1-1/4" Shaft Outside Diameter
  • 4" Overall Length
  • 3/4" NPT Internal Thread
  • Pre-set at Aprox. 10lb Pressure Relief
  • Approx. Flow Rate (gallons per minute) 10 psi=7 GPM, 15 psi= 13 GPM, 20 psi=19 GPM

316L Stainless Steel Quick Engine Flush Connector
Your Price:
$129.99

316L Stainless Steel Quick Engine Flush Connector

620-913300

316L Stainless Steel Quick Engine Flush Connector

Our engineering team has developed this attractive easy to use quick connect thru-hull flushing system. These 316L stainless steel flushing thru-hulls allow the quick connection of a garden hose to this fitting in mere seconds. While the opposite end of the thru-hull features a 1/2" NPT female connection that can be connected into the inlet side of your cooling system or sea strainer. When the garden hose is removed this unit looks like a simple thru-hull yet has a spring loaded internal check valve. Mounting Width: 3-15/16" Depth: 4-3/16"


Quick Engine Flushing Adapter Replacement
Your Price:
$19.95

Quick Engine Flushing Adapter Replacement

620-913301

Quick Engine Flushing Adapter Replacement

Replacement flushing adapter for 620-913300.


Water Pressure Relief Valve 1/2" NPT
Your Price:
$79.99

Water Pressure Relief Valve 1/2" NPT

128-5000

Adjustable  Water Pressure Relief Valve 1/2" NPT

This spring loaded adjustable water pressure relief valve is perfect for bleeding off excess engine water pressure caused by pressure spikes in an engines cooling system.  water flows freely when water pressure exceeds the set designated pressure.  Keep high pressure spikes from damaging your engine.

Adjustable from 7-25 PSI. Flow rate: 1.5 GPM at 10 PSI, 5 GPM at 25 PSI. 


Water Pressure Relief Valve 3/4" NPT
Your Price:
$89.99

Water Pressure Relief Valve 3/4" NPT

128-5002

Adjustable  Water Pressure Relief Valve 3/4" NPT

This spring loaded adjustable water pressure relief valve is perfect for bleeding off excess engine water pressure caused by pressure spikes in an engines cooling system.  water flows freely when water pressure exceeds the set designated pressure.  Keep high pressure spikes from damaging your engine.

Adjustable from 7-25 PSI. Flow rate: 1.5 GPM at 10 PSI, 5 GPM at 25 PSI. 


1-1/4" Pressure Relief Valve Fitting For Inline Use, 1/2" NPT
Your Price:
$39.99

1-1/4" Pressure Relief Valve Fitting For Inline Use, 1/2" NPT

128-5001

1-1/4" Pressure Relief Valve Fitting For Inline Use, 1/2" NPT

This valve should be used in conjunction with the 128-5000 pop off valve.