Multitech 1777.8/7-10 G3 Reassembly of hydraulic system, Seals Gland packing

Multitec

7.4.1Tightening torques - Tie bolts, part No. 905 Material codes 10, 11, 12, 13 (casing: cast iron)

Pump size	Tightening torque Nm
Multitec 32	85
Multitec 50	140
Multitec 65	250
Multitec 100	395
Multitec 125	600
Multitec 150	700
Material code 20 to 30
(Casing: steel or stainless steel)
Pump size	Operating pressure	Tightening torque
	(bar)	Nm
Multitec 32		150
Multitec 50		240
Multitec 65	All	430
Multitec 100		680
Multitec 125		1370
Multitec 150	≤ 40	1500
	> 40	2000

7.4.2Reassembly of hydraulic system

Reassembly of the hydraulic system starts at the suction end and proceeds towards the discharge end. It is advisable to place the pump in vertical position for reassembly. The sequence of reassembly does not pose any special problems and shall be realized in accordance with the detailed sectional drawing and list of components. The components shall be re-installed in the same place as before dismantling.

A clearance of 0.7 to 1.2 mm shall be set between the last impeller 230.1 or 230.3 and the balance drum 59-4 (or spacer sleeve 525.4).

When tightening the tie bolts, proceed as follows:

-Tighten the nuts of tie bolts 905 gently, with the pump in vertical position.

-Set the pump horizontally onto its feet on the assembly table.

-Tighten the nuts of tie bolts 905 in two steps (first step: 50% of nominal torque, second step: nominal torque) in the sequence 1.4.2.3.

12

3 4

Fig. 37

7.4.3Seals

Gland packing

Before re-packing, thoroughly clean the packing chamber and the gland cover.

Caution Packing rings must be inserted so that the cut edge of each ring is displaced by approx. 90￿ to

120￿ in relation to the previous one.

Slip the pre-stressed packing rings onto the shaft protecting sleeve, press home the first packing ring with the help of the gland cover. Each packing ring must be pressed into the packing chamber individually, using the gland cover.

On gland packings with lantern ring (for vacuum operation), the lantern ring is mounted instead of the next to last packing ring (the last packing ring is located in the seal chamber on the pump side).

Tighten the gland cover by hand at first. Use a feeler gauge to check the level position of the gland cover. It must be easy to turn the rotor by hand.

Leakage is normal during pump commissioning. After approx. 5 minutes’ operating period, the amount of leakage can be reduced by steadily tightening the nuts of the gland cover by 1/6 of a turn. Keep an eye on the amount of leakage and the water temperature. It takes several hours of pump operation for the gland to be adjusted completely. There must be a high leakage rate during the running-in period.

Repeat this procedure every 5 minutes until a minimum value is reached.

Dimensions in		Pump size
mm	32 - 50 - 65	100	125		150
Packing	10 j	12,5 j			16 j
cross-section
Length of	≈181	≈223	≈254		≈306
packing cord
Number of	5			6
packing rings
Stuffing box housing

			da
			di
	l
Pump size	di	da	l
32 - 50 - 65	45	65	50
100	56	80	60
125	66	90	72
150	78	110	96

Fig. 38 Gland chamber dimensions

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