TANK SWEEP TECHNOLOGY

NES Tanksweep has been developed as the first stage of cleaning a storage tank where the level of oil or sludge prevents the safe removal of a manway. Once the level has been reduced by using the the Tanksweep and a manway can be safely removed then cleaning may then be carried out in the normal manner using a NES Mover kit or NES Manway Cannon.

Hot/Wet Tapping**

1- weld 18" Flange to manway lid

Hot tapping is defined as using an under pressure drilling machine to cut a hole in an operating oil storage tank allowing a flange to be fitted through which an NESL nozzle may be inserted. This process is done without any product leakage or loss. This operation is safe provided the liquid level in the tank is above the level of hot tapping.

2- Bolt 18" valve to flange

The components for a typical hot/wet tap application include a 18" flange, a 18" valve used to control the new connection, and a drilling machine used to make the hot tap.

The following is the basic procedure used to perform a hot/wet tap.

 

3- fit drilling machine

  • Welding of an 18" flange to a tank manway and fitting of an 18" gate valve onto the flange
  • Install hot tap machine
  • Perform hot tap through the open valve. A special device retains the "coupon" removed during the hot tap operation.
  • Retract cutter assembly.
  • Close hot tapping valve.
  • Remove hot tap machine to allow for inserting of the NESL TanksweepTanksweep" nozzle

 

 

4 - drill through manway lid

5 - withdraw drill

6 - close valve

7 - remove drill

8 -fit

9 - open valve and insert NES Tanksweep into the tank

After completion of steps 1 to 9 the NES Tanksweep is connected to a pump and liquid oil is pumped at the rate of 500 m3/h at 10 bar pressure through the Tanksweep nozzle. The nozzle can be moved horizontally to achieve a sweeping motion with the jetstream of oil from the nozzle. Once sufficient agitation has taken place the liquid can be pumped out of the tank via an existing point or by hot tapping an additional point. Once the level has been reduced to below the manway this operation ceases and the NES Mover is introduced to complete the tank de- sludging

**NESL recomend IPSCO (UK) Ltd as providers of Hottapping services and Hottapping equipment.IPSCO (UK) Ltd Telephone +441724849904 fax +441724861033

 

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