Bissell HS-20 instruction manual Installation, 6. Sight Glass Assembly

Installation

a.The recommended fluid charge for the pump is five U. S. quarts. The fluid charge will gradually be depleted through use, but the pump will continue to operate normally. When the charge is reduced to approximately 60% of the initial amount, the boiler temperature may begin to rise and under this condition the thermal switch is designed to open the heater circuit.

b.This diffusion pump is furnished with fill and drain fittings with special Viton elastomer sealed plugs.

c.If the pump is hot, wait until the pump has cooled then vent it to atmosphere. Remove the plug from the filling port of the pump and install the needed quantity of fluid up to the FULL COLD level indicator on the sight glass (see Figure 1-5). The fluid can also be poured in from the pump inlet or foreline.

d.Replace the fill plug with a new Viton gasket. Tighten the fill plug using moderate torque (75 inch-pounds maximum). Lubricate the O-ring with pump fluid before installation.

e.Once the pump is running, the oil level should be in the FULL HOT operating range as indi- cated on the sight glass assembly.

Figure 1-6. Sight Glass Assembly

NOTE

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It is not recommended that Santovac 5 diffusion pump fluid be used with the HS-20.

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