Spray Lances

The nozzle is separated from the gun by a lance. This is essentially an extension pipe, generally a piece of pipe threaded at both ends. The terms "lance" and "wand" may be used interchangeably. In most cases, these extensions are built with some kind of insulated grip to increase operator control and protect the operator’s hand when hot water is being sprayed.

Longer Than Your Arm
The lance should be longer than the operator’s arm, both for ease in reaching areas to be washed and for safety. The longer lance makes it harder for the operator to spray himself.

Lances can be quite long, especially if made of a lighter material such as aluminum. These lances can be used to reach second story siding from the ground or for other cleaning jobs that may require a considerable amount of "stretch".

Excessive Lance Length Can Be Convenience Or Catastrophe
However, a lance can be too long. The answer to "how long is too long?" depends on the weight of the lance material and the force and angle of the spray. An elbow coupling setting the nozzle at a 45-degree angle from the lance can be used with a spraying lance. However, this angled connection makes the lance harder to handle. Some salesmen use this sort of coupling as a sales gimmick. The angle of the spray against the lance creates a sort of leverage effect that increases with the length of the lance. This makes the thrust of water seem more powerful.

Lances With Two Tubes
Some lances are double-barreled with a high and a low-pressure barrel for chemical injection. A high-pressure nozzle is fitted on one barrel; a lower pressure nozzle is attached to the other. The high-pressure nozzle is used for rinsing and the low pressure for chemical injection. This arrangement works well with a dump gun as well. Lances used with dump guns may have an external and internal tube as well with the pressure nozzle fitted on the internal tube and flow dumped through the external tube when the trigger is released.

Open Lances
Some high pressure washers, particularly older models, do not have a trigger gun. These machines are said to have "open lances". To switch off the water flow the operator has to return to the machine and turn it off. Open lances may be fitted with a pistol grip or simply connected to the high-pressure hose. Usually directly connected lances will have some kind of grip attached.

Operator Abuse
Operator abuse is the major cause of lance, gun, nozzle and hose failure. Most such accidents can be prevented with proper care. It is important to the customer that these items are well cared for by his employees, since these items often carry no or very limited warranties. Here are a few pointers that can save money.
– Use of the lance for any purpose other than spraying water should be avoided.
– The lance should be stored in its rack when not in use.
– The hose should be rolled up and properly stored when not in use.
– The nozzle and hose should be inspected daily before the equipment is operated.

Shorter Lances
Although a 36-inch long lance is the rule for safety, there may be some situations, such as very precise undercarriage cleaning or cleaning in tight areas, where a much shorter lance or mounting the nozzle directly on the gun can make cleaning easier or even simply possible. This type of mounting should generally be avoided at higher pressures. In particularly close cleaning jobs eye protection is absolutely mandatory and skin protection may be necessary as well, depending on the type and concentration of chemical used.

A Number Of Variations

Most variable pressure lances are two-barreled although some designs allow variable pressure control at the lance or gun with a single lance tube. European manufactures market variable pressure lances that are quite short to allow use of downstream chemical injectors in tight spots.

The variable pressure lance allows adjustment of pressure at the lance rather than at the unloader. This type of lance can be used for chemical injection or to vary pressure for different cleaning applications

The Adjusting Handle
The double-barreled variable pressure lance is generally controlled with a handle being a foot or more away from the gun at the point where the lance assembly branches. The handle also serves as a second handgrip to give the operator better, more ergonomically friendly control of the lance. The handle is set in a metal body with one female port on the inlet side and two female ports on the outlet side.

Two Nozzles
A lance extension with a high-pressure nozzle fits in the top outlet port and an extension with a low-pressure nozzle fits in the port closest to the adjusting handle. The low-pressure nozzle has a much larger orifice than the high-pressure nozzle.

The Body And Pressure Adjustment
The handle turns a shaft controlling a movable needle inside the body, which directs water to either the high-pressure nozzle or the high pressure and the low-pressure nozzle. If the needle is seated all the way in its seat in the body, all the water flow is directed to the high-pressure nozzle. When the hand grip is turned to retract the needle from its seat, a potion of the flow is directed toward the low-pressure nozzle. The further the needle is retracted from its seat, the more water flows through the low-pressure orifice. Less water flow is forced through the high-pressure nozzle and less pressure results.

The porting of the body and action of the needle may also be arranged so that the low-pressure nozzle is in the top nozzle extension. Variable pressure lances made by some manufacturers may have a knob on the top of the body rather than a handle. Whatever the exterior configuration, the mechanics of operation remain the same.

Pressure Drops Two Ways
Not only does directing water to the low pressure spray nozzle result in low pressure output from the nozzle, the more water flow diverted from the high pressure spray nozzle, the lower the pressure of the output from the high pressure nozzle.

When the lance is adjusted to produce the lowest possible output pressure, water will still be passing through both spray nozzles but the largest portion of water allowed by the adjusting orifice will be flowing through the larger, low-pressure spray nozzle. The reduction of flow through the smaller, high-pressure spray nozzle will have significantly reduced the output pressure through that orifice as well.