EnviroSpec’s Technical Library

Pressure Wash Hoses

Section: Description

High-pressure hose is constructed of an outer cover, one or more layers of metal braid, and an inner tube. The pressures are available in a range of working pressure ratings. The most common pressure ratings for the pressure wash industry are 3000, 4000, 4500, and 5000 psi. They are measured at the inner diameter. Industry standard is 3/8″, which means the opening that water travels through is 3/8″, with the outer diameter being larger. Most have crimped ends that are 3/8″ male pipe thread, which conforms to the standard inlet port size on a trigger gun.

Section: Bend Radius

Hoses are designed to bend only so far. If you hold a section of hose in both hands and bend it until it starts to become harder to bend, you have found the maximum bend radius. Bending the hose further will damage the wire braid. The outer cover protects the wire braid from moisture that will cause it to rust and weaken. Once the outer cover is torn the exposed braid also becomes a hazard that can cause hand injuries. Hoses should be replaced when the cover is torn.

Section: Burst Pressure

The burst pressure of high pressure washer hoses is higher than the rated working pressure. The standard for burst pressure is four times the working pressure. So the burst on 3000 PSI hoses would be 12,000 PSI. Some hose manufacturers go with a burst pressure of three times the working pressure. This enables them to make a less expensive hose. Most hoses conform to the industry standard. This burst pressure rating is established by testing brand new hoses. Used hoses that have been subjected to run over or twisting loses strength rapidly.

Section: Choosing the Right Pressure

The most common mistake made when purchasing pressure hose is equipping a machine with one that has too low a working pressure. A 3000 psi machine should be equipped with a hose that has a working pressure of more than 3000 psi.  This advice comes from years of field experience using various industrial high pressure water hoses. Always size the working pressure of pressure washer hoses over the pressure washer operating pressure.

Section: Care

Do everything possible to keep high-pressure washer hoses from being run over. The normally round wire braid is crushed when it is run over. When the braid is crushed it develops weak spots that sooner or later result in failure. The higher the psi rating on the the stronger the braid becomes. The stronger the braid the more resistant it is to crushing. Light vehicles damage them less than heavy trucks. Vehicles with pneumatic (inflated) tires cause less damage than vehicles with hard rubber tires, like forklifts. Vehicles running over hose on concrete or asphalt will crush the hose more than on a soft surface like gravel. Hose that is very hot will crush easier than hose that is cold. Hose that is pulled hard when caught on tires or building edges can be damaged. Don’t yank the hose. Avoid pulling hose around sharp corners. This can cut the hose outer cover. When washing on high buildings or roofs, hose crimped ends are not designed to withstand the pull of the hose weight hanging beneath them. When working in this environment use a single hose length or find a way to tie off the hose at intervals that keep the maximum hanging hose at any one interval to less than 150 feet.

Section: Length

Hoses are a wear item. With use they will need to be replaced. That’s why it is usually a good idea to purchase hose in fifty-foot sections. If you generally use one hundred or more feet of hose, there are still very good reasons to use fifty-foot sections. When a hose fails, losing a fifty-foot section and still having good hose enables you to continue working. Having sections of hose also enables you to only use as much hose as you need, saving wear and tear on the rest. One other reason is the cost of custom made lengths of hose. Production made hose lengths are less expensive.

Section: Repair

Because of potential liability problems, manufacturers will not warranty field-repaired hose. Many dealers will not repair hose that they do not sell. There are field repair ends, called reusable hose ends that can be used but are very reliable. Installing a reusable hose end requires the hose be cut cleanly. A chop saw with an abrasive wheel works best. It is very difficult to cut through the wire braid without the proper equipment. The hose section that contacts the reusable end must be undamaged. The outer collar is threaded onto the hose and the insert is threaded into the inner part of the hose. These ends can be used over and over on different hoses. Hose repair becomes a waste of time and effort, as a hose gets older. As a rule of thumb, if a hose section becomes damaged at one end because of improper twisting or stress, hose repair is advisable. If the hose fails in the center because of age or being run over, the repair probably won’t provide much additional use before the hose fails again. Replacement is advisable at this point.

Section: Non-Marking

Black, blue, yellow & red pressure hose will leave lines in many washing situations. Sometimes these lines aren’t acceptable, like when washing concrete. The hose rests in warm soapy water and leaves a line. Non-marking hose is made to eliminate hose marking problems. Gray is the ONLY true Non-marking hose.

Section: Sewer Jetting

Jetting hose is thin, commonly 3/16″ or ¼”. This facilitates its movement through clogged pipes. It also has a very hard thermoplastic cover that is smooth and slippery. This cover gives less resistance so the hose slides through pipes easier. They are available in several pre-cut lengths or in custom made lengths. Unlike pressure wash hose, using a single length is wise because it can’t come apart inside a pipe. These hose are generally used with a sewer-jetting nozzle.

Section: Strain Reliefs

Stain reliefs are common on each end of a section of pressure hose. Their purpose is to prevent excessive bending at the fittings. Industrial high pressure water hoses generally receive some of the worst abuse at the ends. The end at the trigger gun is strained by the weight of the hose dragging behind it, and it is constantly twisted at the trigger gun inlet. Operators who run without enough hose commonly will pull too hard and put a lot of stress on the hose where it is connected to the equipment. Strain reliefs should be on the crimped fitting shoulder and extend down the outer cover of the hose.

Section: The “Whip”

The hose whip is a one-foot section of pressure hose that is installed at the trigger gun inlet. Its purpose is to remove the longer section of hose from the area of most stress. It also removes quick connects from the same area of twisting and makes them last much longer.