Unloader Valves

Unloader Valves

NLB water blasting units use positive displacement reciprocating pumps.  This means that when they are on, they are constantly pumping water.  Since shut-off-style lances and foot controls have no built-in means of dumping pressure, the safest way to use them is with an unloader valve.  These are activated when an operator releases the trigger of the lance.  This essentially shuts off the outlet for the water.  When this happens, the unloader valve opens and dumps the water.

In automated applications, unloader valves can also be used to divert water back to the tank when the flow is shut off at the work site.  NLB offers 25 gpm (UL-452) and 50 gpm (UL-904) models, both constructed of stainless steel for long life.  Repair kits are available.

Part NumberMax. PressureMax. FlowInlet ConnectionOutlet Connection

$1.00 Add to Quote

UL-45210,000 psi max.
(700 bar max.)
25 gpm
(95 lpm)
1/2" NPT1/2" NPT

$1.00 Add to Quote

UL-90410,000 psi max.
(700 bar max.)
50 gpm
(190 lpm)
1" NPT1" NPT

Related Products

dry shut-off guns

Provides a means for completely stopping the flow of water the at the work site when an operator releases the trigger

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dry shut-off foot controls

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whip hoses

Whip hoses helps protect operators from potentially dangerous hose failures

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Additional Information

Max. Pressure

10,000 psi max. (700 bar max.)

Max. Flow

25 gpm (95 lpm), 50 gpm (190 lpm)

Inlet Connection

1/2" NPT, 1" NPT

Outlet Connection

1/2" NPT, 1" NPT