On nearly all the machines we supply, customers ask us for a Harben® MkII jetting gun. Jetting guns can be used to increase the productivity of a machine and bring in additional paid work that the owner may not have originally considered – jobs like cleaning buildings, washing pavements or jetting garage forecourts – but it is important that owners and operators understand the new British Standards* covering jetting gun use.
When water blasting with a gun, the jet nozzle creates a force that pushes the operator backwards and can make them unstable. This is called the reaction force and higher pressures or greater flows can increase it considerably.
The force that an operator is allowed to handle before it is necessary to add a shoulder stock to the gun is 150N, roughly the same as supporting a weight of about 30lbs. Most professional drain cleaning machines are capable of generating forces this big.
Measuring the reaction force that your gun produces is difficult, so Flowplant has created a simple Reaction Force Diagram that allows you to quickly check what it will be, along with two examples of flow/pressure combinations.
Of course, if you are still unsure, then just give our Technical Hotline a call on 01722 344091 and we will work it out for you.
Our Harben MkII jetting gun is available with a shoulder stock kit (Pt No. 7001931), that can be supplied with all new guns, or as a simple retrofit kit. Remember, even when reaction forces are below 150N, the new shoulder stock will make handling the gun much easier over long periods.
*BS EN 1829 Part 1, covering guns with a max working pressure of 350 bar or above