Flushing

Ideally, system pumps should not be used for flushing.
The only satisfactory solution is to use an independent flushing unit.

It is essential for effective flushing for the flow to be turbulent. Ideally, the turbulence during flushing should be equal to or greater than that which occurs in the system when it is operating under the most difficult conditions. We recommend a rate which is at least 1.5 times turbulent rate, but always the Reynolds Number should be 4000 or more.

flushing

High velocities must also be achieved in order to transport the contamination out of the pipework.

DGH manufacture units with add-on accumulator banks to provide large “slugs” of turbulent flushing flow without relying on huge horsepower requirements.

The discharge from the pressure accumulators produces pulsation and vibration within the pipe system during the flushing operation. The hydraulic hammer effect created opens the texture in the pipe walls and shakes loose even the most stubborn contamination. This is then transported out of the piping system by the high velocity flow. A lower flow is maintained whilst the accumulator is recharging. This helps to keep the contamination suspended in the fluid and facilitates entrapment at the return filter.

DGH units use quality filters (Beta ratio 200:1) on the return side; pressure filters can be fitted if required. The pump has nominal 125 micron suction protection by means of an in-tank mounted strainer.

In addition to our standard range of units, we can purpose manufacture to suit specific applications.

An additional feature of these impulse rigs is that they will comprehensively test joints and bracketing. The severity of the applied shock (which is adjustable), will comprehensively test new piping installations and
ensure confidence on commissioning.

OPTION 1

1 off 22Kw 415v 3ph 50Hz electric motor driving a double pump of-270 litres/min and 49 litres/min at 35 bar. The 270 litre/min pump may be offloaded and the small pump can then be taken up to 170 bar

OPTION 2

1 off 18.5Kw 415v 3ph 50Hz electric motor driving a single pump 270 litres/min at 37 bar complete with relief valve, pressure filter Beta 200:1, pressure test point, HP isolation valve.

1 off 7.5Kw 415v 3ph 50Hz electric motor driving a single pump producing a flow of 17 litres/min at 250 bar.

ACCUMULATOR BANK

Typically a bank of accumulators mounted in a fabricated frame c/w isolation and blow down valves.
Maximum discharge flow rate is 750 litres/min per accumulator.

Additional accumulators can be provided where higher flow rates are required.

Control of charging and discharging can be by manual or solenoid operated valve (state preference when
ordering).

We can also provide

• CONTAMINATION CHECKING SERVICE
• SERVICE TECHNICIAN ENGINEERS TO OPERATE RIGS AS REQUIRED