Hawk Pumps, manufacturers and distributors of quality high-pressure pumping and cleaning equipment, shares insights into high-pressure tube and drain cleaning and the different nozzles used to remove the different substances causing restrictions and blockages.
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Pipe cleaning machines have various requirements in order to function at their best. Some of the problems these machines need to be able to overcome include the following:
- Boiler and heat exchanger tubes generally get a layer of various types of scale that restrict water flow and reduce heat transfer. This lowers the flow and increases the amount of fuel needed to overcome the insulating effect of the scale.
- Slurry transfer pipes in various industries tend to become restricted by solids deposited on the internal walls of the pipes.
- Waste drain pipes in industry, hotels, hospitals and garages suffer from deposits of grease and other sticky materials, especially from kitchen waste.
- Sewers are notorious for clogging, usually from foreign objects being flushed into the system.
- Rain water drain pipes and storm water drains tend to have litter and sand settling in the bottom of the pipes, eventually blocking them completely, causing flooding during rain storms.
Pipe cleaning machines all have one thing in common: they need special nozzles designed for each specific application. High pressure pump machines are readily available or can be custom designed, but the choice of the correct nozzle, water flow and pressure is very important.
The various types of nozzles have a few things in common. Most have jets facing backwards, which serve two main purposes; to pull the hose into the pipe and to clean the pipe’s walls. For cleaning walls, the jets tend to face backwards and outwards at a large angle. Sometimes, a forward facing jet is not necessary, which allows larger, rear facing jets to be fitted.
If the problem is a blockage, a forward facing jet is important, because the rear facing ones don’t spray outwards as much, making it harder for the forward pulling power to overcome the negative effect of the forward jet.
Boiler tube nozzles usually require relatively low volumes at higher pressures to cut through the scale, which can be extremely hard. They don’t depend much on rear jets and don’t have front ones, but rather have side jets on a spinning body. Occasionally, when the tube is all but blocked, a chisel nozzle with sharp hardened facets in front is needed to physically break the scale with forward facing jets. These nozzles are fitted to rigid pipes, rather than flexible hoses. The pumps needed here have low volumes of about 20 ℓ/min at 500 bar pressure.
Slurry transfer pipes require simple ‘bomb’ shaped nozzles with rear facing jets. Here, depending on the pipe diameter, a medium volume pump, typically 80 ℓ/min of flow at about 150 to 200 bar is used. Occasionally, a nozzle with spinning chains will be needed to improve the cleaning effect.
Waste drain pipes are also usually cleaned using ‘bomb’ nozzles and require pumps similar to the slurry pipe applications. If the pipe is blocked, a nozzle with a front jet is called for, while hard blockages need cutter nozzles.
Sewers vary in diameter and have different degrees of blocking. For normal domestic sewers, a 30 ℓ/min pump at 150 to 200 bar will suffice. The nozzles required are simple mini-bombs with forward and rear facing jets. Mains sewers are of a large diameter – up to 300 mm but usually about 200 mm – and these require a minimum of 80 ℓ/min at 150 to 200 bar. A
120 ℓ/min pump helps to pull the hose better, especially where the sewer has a long space between manholes. Cutter nozzles, chain flail nozzles and bomb nozzles are all used in this application.
Rain water and storm water drains require much larger pumps. They usually need 150 to 200 ℓ/min at 150 to 200 bar. Bomb nozzles can be used, but where sand is the main problem, the ‘flounder’ nozzle is the most effective. This nozzle consists of a block of metal with a pointed front and usually four rear facing nozzles. When the nozzles reach sand, they tend to ride up and over it and, in doing so, cause the rear jets to agitate and fluidise the sand. The large volume of water carries the sand back to the manhole where it is removed, either physically or by means of a jet pump that only needs a small portion of the pump flow to push the sand out.
Hawk is a manufacturing company that primarily creates industrial high-pressure pumping and cleaning equipment. They also manufacture spraying solutions, including industrial nozzles. One of Hawk’s biggest differentiators is that they have the capacity to manufacture and custom design machines tailored to specific customer needs.
Hawk serves a wide range of customers from virtually every industrial sector, including processing plants, factories, workshops, contract cleaners, drain & sewer cleaners, car, truck & bus washes, mines, agricultural and more.
