An SRL Pump Barrel Assembly provides a key housing parts for the two steady bearings that are required to keep the impeller shaft steady. To keep these bearings lubricated the barrel is half full of oil.
For the operators convenience there will be either a dip stick or a sight glass to check oil level with. Part of the barrels construction will be an oil seal at either end of it.These are there to keep the oil in the barrel.
On the far end of the impeller shaft is a drive sheave, this provides a link, by way of V-belts, to the electric drive motor.