Inspecting flooded pumps and mainlines

[Pat Daley from Daley Water Services]

Part 1

Today we're looking at a submerged electric turbine pump and you can see there by the debris how high the water has got.

Some of the areas we will look at with the pump will be: the switch gear or control gear, the motor itself, and the pump discharge, also the borehole assembly.

This is a hollow shaft electric motor and most hollow shaft electric motors are important to have air through them to cool them.

The shaft goes up from the pump through the centre of that motor and we've got a vent here and a vent at the top so it is important to, one, make sure that there is no debris closing those off, but in the case where it has been completely submerged, it is a good idea to remove the hollow shaft motor and have it looked at by an electrician. The electrical people will pull the motor apart and dry out all the bearings and wiring.

The procedure to pull the motor off is that at the top there under the hood, there's an adjustment nut with a locking screw. It is important to note where that locking nut is, and where the locking screw is, when you need to reassemble the unit. So it is just a matter of undoing that nut, and the shaft will drop down slightly and you use the lifting lugs on the motor to lift that motor off the shaft.

To lift the motor you need something that has a straight pull. A loader is very cumbersome to do something like that because as it lifts higher, it pulls in closer to the tractor which could bend the shaft.

Part 2

The areas that need to be looked at are the things like the discharge head. You can see that there is a lot of build-up of stuff around this discharge head that would need to be removed. Anything like this that builds up around the packing gland – the packing gland is the piece that seals the water from coming out and pushing up into the electric motor, and also stops things from going down inside. If you have got sediment built up around the packing gland inside there you could wear the shaft out.

I can see looking in here that there is some deposits of sediment there - if you were to run this pump before you cleared that it would grind away on that shaft.

The other areas that would also be looked at is to make sure that there is no, if there is any air gaps around between this discharge head and the bore cap you could get sediment that goes down inside the bore. So it is important to check that hasn't happened. Fortunately with this pump nothing – it's all sealed with a rubber...some insertion rubber.

The other areas that you might look at are things like the pre-lube tank (which has floated away in this case) but this hose here is normally connected to a small tank that puts water down inside the pump to lubricate the rubber bushes. It is important to make sure there is no sediment in there because that sediment will wash straight to the bearings.

Part 3

We move onto the electric components – obviously if these have been under water like this one, all this needs to be looked at by an electrician. It doesn't mean that it automatically can't be used or that it has got to be replaced. Quite often it just needs to be thoroughly dried out. But an electrician needs to check them out.

And once again remove some of this debris.

The other thing that can happen even if the control mechanism doesn't go under water it is a good idea to thoroughly check because you get all sorts of critters, ants, frogs, what have you that want to get up to higher ground and live in these boxes. It is amazing with a small opening what size animal can get inside.

All the glands and the cabling on the control boxes need to be looked at to make sure there has been no logs, or things like that, which could have pulled these out, and make sure they are tight. The electrician would normally pull those cables apart because quite often you will have water that would sit inside these conduits and that needs to be drained out.

Part 4

When we move onto the discharge of the pump there are things like this air valve here that we can see there are deposits of sediment, grass and things in the valve there. That all needs to be pulled apart and cleaned out for it to function correctly.

The other areas is the flow meter. The flow meter should be relatively safe from submergence. However, some of the electronic readers are not submergible – they're only drip proof.

[Pat Daley from Daley Water Services]

Part 1

Here we are today we are looking at a submerged engine-drive turbine pump. Today we are going to go through the steps to ensure the pump will be running back to its original state.

The fuel system is rather important. The fuel needs to be drained if you have got water inside. If there is no water inside leave the diesel fuel that is in there. The fuel lines, both the intake and the return lines need to be thoroughly blown out and disconnected from the tank to ensure there is no water or sediment buildup in those tubes.

Most times you should be able to quite safely leave the diesel in the fuel pump but it is still a good idea to check that. We would also drain the oil from the sump. We would also go to the injectors and we would undo the injectors at these points, and lift the injectors and squirt diesel and a little bit of oil into the top. That will sit on top of the pistons and stop any erosion starting straight away.

One of the other things with the fuel system – we need to check whether or not the bulk fuel tank has got a pre-filter and water trap. Normally that would be where the intake line is, and you can see on this one that it doesn't have a filter to check. In this case you would undo the tube and take some samples of the fuel within the tank to ensure it has no dirt or water in it.

Part 2

Other areas that we will look at is the radiator. The radiator can get buildup of sediment with the cores – that needs to be blown out. After you get the engine up and running again the last thing you need is for it to overheat in a few hours of operation.

It's a good idea to go through and change the coolant in any case, while you're doing the rest of the engine.

Part 3

The air cleaner needs to be thoroughly inspected for any water intrusion and sediment. And regardless, it is a good idea to change the filter and make sure you have cleaned all the sediment out.

If water has gone over the top of this you may need to drain the manifold – in fact, it's a good idea to drain the manifold to inspect if there is anything inside there.

Just moving across to the exhaust – you can see that this exhaust pipe, if it got water in there it would be very hard to remove the water from out of the manifold. So that needs to be dismantled and drained all the water from that section.

Part 4

Automatically you would be looking at things like your starter motor, alternator, the circuitry that charges the battery and even the battery for that matter – if it is an unsealed battery it could have sediment inside it. This engine also has a protection on it for oil pressure, water temperature, water level and pump pressure.

It also needs to be looked at by an auto electrician as well.

Part 5

One of the things we need to check also is whether there has been any subsidence with the framework that the engine sits on.

Obviously if it gets out of square with the drive head that could have some long-term problems with wear and tear.

On the engine itself it is important to have a look at the flywheel end and just see whether or not there is any sediment buildup in that flywheel. Along on the discharge pipe of this pump there are things like the air release valve – quite often sediment can get into the inside of that valve.

The next piece of equipment on this is the flow meter. The flow meter should be okay under water but some of the readers are not submergible – so they might need to be looked at at a later date.

[Nathan Bradley, property owner]

In this situation Pat, where the water has been over this pump for – possibly at the longest period it was probably under water for at least 12 days – what is the best things to look for? The first thing I would do is obviously clear the debris and then the telescopic slide shaft there and give that a grease ... even though they are greased every day but it has been under water for a long time. The rubber coupling, I mean, whether there is crap in that, whether it needs to be cleared and then obviously all the bearings inside the pump.

[Pat Daley from Daley Water Services]

That's for sure, Nathan, the debris that you can see obviously, but some of the things that you can't see like sediment inside these tyres ... which can not wear everything out immediately but it sends the balance of the shaft ... could be put out of balance quite a bit and that will load up these bearings and also it gets magnified into the back of the engine.

So particularly with high speed engines, this one would not be running at high speed but quite often with high speed engines the tortional vibration that goes into that fly wheel can damage the crank shaft ... so a lot of damage can be done from simply the sediment inside that tyre. They are not an easy thing to pull apart and check but it is well worthwhile in trying to clean it out.

The other areas are that as you stated are that you would grease, well this a good idea to give it probably a little more grease just to see whether any water droplets come out of the bearings ... because if there is any water in there then the temperature when you get the pump going the temperature rises fairly quickly and that's what does the damage to the bearings.

[Nathan Bradley]

Is it a good idea for this time to possibly use high temperature grease instead of general purpose grease?

[Pat Daley]

I would probably go for high temperature grease because it is a little bit higher density as well so it will take up some of those water droplets out of there. The other areas are any of your seals just to make sure the debris is completely clear from the seals, and even the telescopic shaft that you mentioned while it is not a high moving part you will get wear in there if there is sediment sitting in on top of the telescopic shaft.

As far as the pump itself goes any of these pumps that have got a packing gland which that is really the way you are sealing the air out of the pump so that you can prime the pump and keep the prime ... while inside there is gland packing as you would have seen. If you get deposits of sediment in there and you are running it, it will grind away at the main shaft, so it is a good idea to back those nuts off a bit and get an air compressor and blow around the gland packing and just do them back up again as normal. In case you are not sure with gland packing it should have about 5 drips a minute is what you need. You don't want to stop the water coming out because it will burn the shaft and the packing.

The bearings here once again you grease those and look for any signs of water bubbles coming out through the seals cause the seals are not good enough to keep the water in there so the grease pressure will push that water out. If you do see a lot of water in there that's when you would probably look at pulling it apart. But certainly look for the signs of water first. It's the same as for that counter shaft bearing here of course, grease it and observe whether any water bubbles come out.

Moving away from some of this moving stuff though, the other things I do look at the water source that might have changed down there so next time you go to pump you don't want to be putting sand and stuff though the system and you might want to make sure you have a pumping hole there ... and on the discharge here we have an air valve on the non return valve chamber there where you just make sure nothing has built up inside and things like that. But other than that it would be good to go.

[Pat Daley from Daley Water Services]

Today we're at a flood-affected area where erosion has eroded along the length of a piece of mainline.

This is the type of thing that needs to be inspected after a flood event.

A lot of mainline is only supported by the dirt around the mainline.

Particularly rubber ring joint pipe where the concrete thrust blocks is what holds all the pipeline together and the dirt over the top.

So if you get areas like this that is exposed, and you start the system without backfilling this erosion, you can very easily pop the pipe out of the ground.