I there are two hole pre-drilled in the bottom of my 180g. The larger one is about 1-5/8" dia and the second is about 1-5/16" dia. When I started looking into bulkhead fittings for these holes, the pipe size a bulkhead to fit into these holes is small. For instance to get a bulkhead to fit into the 1-5/8" drilled hole, the pipe size is 3/4". IS this right. Do I get that size bilkhead and then enlarge the pipe immediately before and after the bulkhead?
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Hole Size vs Bulkhead Size
- Thread starter NEWSALT
- Start date
Here’s the Schedule 40 and 80 bulkhead sizes versus hole size:
HOLE SIZE
BULKHEAD Schedule 40 Schedule 80
1/2 1 1/8 1 3/8
3/4 1 1/2 1 5/8
1 1 3/4 1 7/8
1 1/2 2 3/8 2 5/8
2 3 3 1/4
In my opinion, increasing pipe size before/after bulkhead isn’t going to buy you much, if anything.
The line going down to your sump is gravity fed and limited by the smallest opening (and length of pipe and number of elbows). Increasing the pipe diameter just before the bulkhead might give you slightly larger head pressure, but I think it would be minimal.
The return line is under pressure and, without doing calculations and knowing the type of pump, if you were to use larger diameter pipe before/after the bulkhead, you would also be increasing the weight of the water column that would need to be pushed up. My guess is that this would cause for less return flow than just keeping the normal diameter of the bulkhead. It is under pressure so the return shouldn’t be that much of a concern.
If you have the room around the holes you could always increase their diameter. The limit is the amount of space in the overflow and the proximity of the other hole. The other option is to consider what I call the poorman’s bulkhead. Make your own bulkhead by using a threaded male adaptor (threaded one end, slip the other) and a threaded female adaptor. Just need to pick up or make a gasket. Not sure of the size…but they are dirt cheap fittings. Might be able to get up to 1 ¼ inches.
HOLE SIZE
BULKHEAD Schedule 40 Schedule 80
1/2 1 1/8 1 3/8
3/4 1 1/2 1 5/8
1 1 3/4 1 7/8
1 1/2 2 3/8 2 5/8
2 3 3 1/4
In my opinion, increasing pipe size before/after bulkhead isn’t going to buy you much, if anything.
The line going down to your sump is gravity fed and limited by the smallest opening (and length of pipe and number of elbows). Increasing the pipe diameter just before the bulkhead might give you slightly larger head pressure, but I think it would be minimal.
The return line is under pressure and, without doing calculations and knowing the type of pump, if you were to use larger diameter pipe before/after the bulkhead, you would also be increasing the weight of the water column that would need to be pushed up. My guess is that this would cause for less return flow than just keeping the normal diameter of the bulkhead. It is under pressure so the return shouldn’t be that much of a concern.
If you have the room around the holes you could always increase their diameter. The limit is the amount of space in the overflow and the proximity of the other hole. The other option is to consider what I call the poorman’s bulkhead. Make your own bulkhead by using a threaded male adaptor (threaded one end, slip the other) and a threaded female adaptor. Just need to pick up or make a gasket. Not sure of the size…but they are dirt cheap fittings. Might be able to get up to 1 ¼ inches.