FAQ

No, clean dry air only

The blower units are not leak proof, leakage is normal, and doesn’t affect the specified flow rate of unit.

None, Gast blowers are oilless, and do not require oil.

No, none of Gast models are designed to pump combustible gases.

Wiring information is included in your owners manual, if the manual isn’t available you can go to www.gastmfg.com.

No, they are not for filtration. They are designed for sound reduction, an inlet filter should be sourced separately.

If your model is 1.5 horsepower and above you should have a relief valve installed on your unit.

The blower may overheat, heat can cause thermal expansion of internal parts resulting in impeller strike, which will score the impeller and housing, and most likely lock up the unit resulting in catastrophic failure of unit.

Gast does not sell motor starters, it must be sourced separately.

Soil vapor extraction models (models ending in -50, like R3105N-50) must be sent to the factory for refurbishing, these units are sealed to a certified leak rate, which must be done at the factory.

For an explanation of the Blower model numbers please click here.

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No, clean dry air only.

They serve as spacing between the retainer plate and the valve plate. They must be kept in the same location to ensure proper alignment.

None, Gast diaphragm units are oilless, and do not require oil.

No, none of Gast models are designed to pump combustible gases.

With the power disconnected from unit, insert a rigid instrument through the grill and rotate the cooling fan a few times. This should loosen the diaphragm and allow the unit to start.

Gast flushing solvent, AH255D. If this is not available you can use electrical contact cleaner.

Yes the kit will contain parts for new and old style units.

Yes the brushes can be obtained from Gast distributors. Check website sales & distribution for a distributor near you.

The motor can not be replaced in the field, the unit should be sent to an authorized service center.

The rod assembly is not field replaceable, the unit should be sent to an authorized service center.

For an explanation of the Diaphragm model numbers please click here.

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No, clean dry air only.

The piston unit is not leak proof, leakage around the head is normal, and doesn’t affect the specified flow rate of unit.

None, Gast piston units are oilless, and do not require lubrication.

No, none of Gast models are designed to pump combustible gases.

The unit is wired for high voltage from the factory, check the motor label to see how to rewire unit to for low voltage.

Gast flushing solvent AH255D, if this is not available you can use electrical contact cleaner.

Yes, check the operation manual for kit required. If you don’t have the manual, go to Technical Documents and choose manual.

Rings, seals, rider ring, intake & exhaust valves, and gaskets for the head and cylinder.

The motor can not be replaced in the field, the unit should be sent to an authorized service center.

The rod assembly can not be replaced in the field, the unit should be sent to an authorized service center.

For an explanation of the Piston model numbers please click here.

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No, clean dry air only.

Most likely foreign material has gotten under one of the valves holding it open, causing low flow.

None, these models are oilless, and do not require oil.

No, none of Gast models are able to pump explosive gases.

ROC-R models will not restart under any load, the head must be unloaded for proper restart.

Gast recommends using Gast flushing solvent AH255D, if this is not available you can use electrical contact cleaner.

These are shims to protect the retainer plate from hitting the vale plate, if removed, they must be reassembled the same way they came off. If one is lost it must be replaced to assure proper clearances.

Yes the brushes can be obtained from your nearest Gast distributor, look on our web site and click on sales & distribution.

The motor can not be replaced in the field, the unit should be sent to a rebuild center.

The rod assembly is replaceable, refer to your owners manual for part numbers.

Preventative Maintenance (PM) kits should be installed every 2000 hours or 2 years, whichever comes first. Additionally, if fitted with Sound Shield, the AS321 Silencers should be replaced during the same interval period.

If properly fitted and operated under normal conditions of use, the remainder of the factory warranty will continue with Sound Shield installed.

For an explanation of the Rocking Piston model numbers please click here.

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Yes, a check valve should be placed inline for either pressure or vacuum applications.

Vane breakage and increased potential for ingestion of foreign debris can result from running units in wrong rotation.

Filters should be inspected, cleaned and/or replaced every 500 hours.

Rotary vane units can be used for either vacuum or pressure except for separate drive lubricated models which are designed to be model specific for vacuum only or pressure only.

All separate drive units may be pulley-driven with the exception of the 67 series which require a 56C NEMA frame motor and must be direct coupled.

The max speed for a separated drive unit is 1,750 rpm.

Lubricated models require AD220 oil. Oilless model do not require lubrication.

You can buy AD220 oil form your local Gast Distributor.

AD220 is 10wt. SAE high detergent petroleum base oil. Any substitute should be the same. Do not use synthetic oil blends.

Use the fill line on the oil reservoir to gauge oil consumption.

Lubricated motor mounted units use siphon lubricators which are preset to dispense appropriate amounts of lubricant. Lubricated separate drive units use gravity feed lubricators which can be adjusted to reduce oil feed rate by adding more wicking material to base of oiler.

Remove the end plate of the unit allowing access to the vanes. Remove the vanes from the unit. Use AH255D to flush out the inside of the unit, end plate and vanes. Blow out the inside of the pump, and wipe down the vanes and reassemble the unit. You should also replace the filters at this time.

No, the bearings are shielded or sea

Gast AH255D flushing solvent. You should NOT use any solvent that is petroleum based, electrical conductive or flammable.

No, units are designed to be used for ambient air only. You should never pump a liquid with your unit. Doing so can result in vane or rotor breakage.

No, Gast rotary vane units are designed for use with ambient air only.

Yes, water vapors may cause unit to rust or corrode, if ingested and allowed to sit idle for a long period of time. To help prevent your unit from rusting, follow the proper shutdown procedure defined in the operation and maintenance manual.

Proper shutdown procedures must be followed to prevent pump damage. Failure to do so may result in premature pump failure. Units are constructed of ferrous metals or aluminum which may be subjected to rust or corrosion when pumping condensable vapors such as water. Follow the steps below to assure correct storage or shutdown of the unit between uses:

After using the unit, disconnect it from your application and allow the pump to run open for at least 3 minutes.

Block the inlet port and let the pump to pull a deep vacuum on itself for at least 5 minutes. (this lets the pump get very hot and will dry out any moisture that the pump has ingested, for lubricated models, it also helps the unit pull in extra oil to protect it)

Turn off the unit but DO NOT break the vacuum, let the unit break the vacuum level through natural leakage as the unit comes to a stop. The unit is now ready for storage.

On the side of the motor you will find a motor manufacture information label and on this label it will show or tell you how to rewire the unit for low voltage just follow the directions listed there.

Yes, repair kits are available for most units, check the operation and maintenance manual.

Most kits will provide everything needed for basic repair, along with an operation and maintenance manual.

In most cases all you will need is a socket or box wrench.

Check service area of website for list of global authorized service centers.

Check sales and distribution area of website for the distribution representation for your area.

For an explanation of the Rotary Vane model numbers please click here.

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Yes, Gast offer repair kits for most models.

No, lubrication is not required.

Most models come with a sound attenuator to reduce noise.

Yes, Gast does offer a line of vacuum cups.

Gast vacuum generators can be mounted in any position.

AH255D flushing solvent can be used to flush unit.

For an explanation of the Vacuum Generator model numbers please click here.

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