Howden Roots Air Blower URAI 33

Check for rubbing between impeller and casing

Observe surfaces for spot heating

Inspect for sudden bearing failure

Check oil level in gear housing

Is the temperature at the bottom of the gear housing unusually high?

Inspect for gear tooth-clearance and backlash

Check for impeller contacts (knocking)

Technical supplement for URAI-G Gas blowers — Precaution

Ensure care is used when opening the head plate seal vent chamber plugs (43)

Is the system under pressure or vacuum?

Check for gas leakage through the mechanical seals

Verify if gas leakage is escaping through the gear box vent or grease release fittings

Is the gas leakage undesirable?

Purge each seal chamber with an inert gas if leakage is undesirable

Ensure purge gas pressure is maintained one PSI above the discharge gas pressure

Check for gear end oil and drive end grease leakage into the gas stream

Lubrication for Units with Grease Lubricated Drive End

Verify applicable speed and operating hours

Use specified NLGI #2 premium grade aluminium complex grease, Roots P/N T20019002

Ensure no lithium based grease is used

Technical Supplement for URAI-G Gas Blowers — Lubrication

Check hydraulic pressure relief fittings for proper venting

Ensure restriction plug and metering orifice are in place

Slowly force new lubricant into each drive end bearing housing until clean grease appears at relief fitting

Avoid using electric or pneumatic grease gun

Lubrication — How to properly determine the oil service intervals

Enter the discharge air temperature of the blower in °F

Calculate the estimated oil temperature by multiplying the discharge temperature by 0.80

Is the estimated oil temperature 180°F (82°C) or less?

Select the ISO Viscosity Grade based on conditions

Remove the oil overflow plug (21)

Fill the reservoir up to the overflow hole without overfilling

Lubrication — How to properly determine the oil service intervals

Check ambient temperature and discharge temperature

Determine oil viscosity grade based on temperature

Verify the specified and recommended oil is Roots synthetic oil

Remove the breather plug (25) and the oil overflow plug (21)

Fill the reservoir up to the overflow hole

Ensure the reservoir is not overfilled

Place the breather and the overflow plug back into their respective holes