Jesco MAGDOS DE/DX Operating Manual

Jesco MAGDOS DE/DX Operating Manual Manual pdf 20 page image

9.1.1 Automatic ventingThe automatic venting facility (standard features on DE/DX 03, 07 otherwise optional extra) consists of anon-return ball valve. The ball ③ rolls against the seat during the suction stroke and away from it during thepressure stroke. The stroke length of the ball is determined by the screw ②. Starting from the position atwhich the screw blocks the ball, turn the screw by half a turn to the left and start the dosing pump. Depend-ing on theoperating pressure that may already be applied at the discharge valve ③ , the dosing pump is primed untiluntil the metered medium emerges from the vent outlet ⑤. Now tighten screw ② until medium no longeremerges and the dosing pump assumes normal delivery.To regularly dispose of gas collected in the dosing head, a certain permanent, unavoidable leakage quantityis to be established (approx. 25 - 30% of the dosing rate, corresponding to approx. 0.5 - 0.7 l/h on theDE/DX 2) which flows through the vent outlet ⑤ via a 4/6 PVC hose back to the supply tank. The leakagequantity is set by carefully turning screw ② and locking nut ④.The leakage quantity depends on the operating pressure. If the operating pressure is subject to fluctuations,the consistency of the leakage quantity and therefore of dosing itself can be increased by installing a pres-sure control valve. The pressure control valve should be set approx. 0.5 bar above the maximum expectedoperating pressure.⑤④ ③② ①20 | Operation & Maintenance Instructions | Start-up