Dultmeier Sales will be closed Thursday, November 25th and Friday, November 26th in observance of Thanksgiving

Dultmeier Sales will be closed Friday, December 24th.
Normal operations will resume Monday, December 27th. We wish you and your family a very Merry Christmas!

Dultmeier Sales will be closed Friday, December 31st in observance of
New Year's Day

Dultmeier Sales will be closed Monday, July 5th in observance of Independence Day.
Normal operations will resume Tuesday, July 6th. We wish you a happy 4th of July!!

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If you are running into issues, please phone your order in to 1-888-677-5054

Customer Pickup Orders: to help reduce exposure for our customers and our employees, if you are placing an order for in-store pickup please call in your order ahead of time or place your order online and pre-pay with a credit card. Be sure to let us know when you plan to arrive. We will have your merchandise ready for you and will greet you outside our facility. Thank you for your help!

Unloader Valve Basics | Video

An in-depth video description of how an unloader valve works. The video also covers common problems found within unloader valves. The video is specific to an unloader valve seen in a hydraulic system.


An unloader valve is a type of pressure control valve that is used to dump excess fluid at low pressures. There are several types of unloader valves, such as direct-acting or pilot-operated. Direct-acting valves consist of a spool held by a spring. When pressurized fluid flows into the valve, putting pressure on the spring. When the spring setting is reached, the spool opens and fluid is bypassed to the tank. Pilot-operated valves work much the same, although there is an additional spool called the unloading spool. This spool opens when pressure in the circuit goes above settings. This allows fluid to enter the tank with minimal pressure loss.