What size BulkHead

  • We are currently upgrading MFK. thanks! -neo
Monolicious

Monolicious

Blue Tier VIP
MFK Member
Mar 17, 2008
762
2
323
55
ON MFK
Hi guys I am currently setting up my 450gal It has two 25mm or 1 inch bulkheads in the rear of the tank , Are these going to be big enough to cope with 4500 LPH. :confused:

Any help would be greatly appreciated.

Regards


Peter
 
When I looked into this a while ago 1" ID pipe is good for 1000gph as long as the length of piping & number of bends isn't excessive. So, at 4500lph you're right at the upper limit of 1" bulkheads. It also partly depends on your pump. A pump capable of producing greater pressure will be able to get more flow out of a given pipe diameter.
 
So does that mean with 2 x 1" Bulkheads I should be getting 2000 GPH
if so will this be enough to filter a 450 G tank ???

The Bulkheads heads are feeding my double sump 1 either side and I am useing an eheim compact + 5000 pump to return the water back to the tank.
 
With the two 1 " Bulkheads I should be getting 2000GPH = 7500LPH The eheim pump is rated at 1320 GPH = 5000 LPR so in theory the bulkheads will be capable of flowing more than the pump. In turn that should be giveing me just over 3 times the total turn over of water.

Correct me if I am wrong, It's just I have already bought the bulkheads and fittings but have yet to silicone them into place.
 
Also...
I wouldn't use silicone on the bulkheads...They are designed to seal with the flat rubber washer supplied with the bulkhead...

Make sure to clean the glass good first.
Put the rubber washer on the inside of the tank. Put the bulkhead through the Rubber washer, then through the glass.
Hold the bulkhead in place, and tighten down the nut outside the tank.
DON'T let the bulkhead spin, just tighten the nut OUTSIDE the tank...
they do not need to be cranked down to seal the bulkhead...After contact, about 1/2 to 3/4 turn will be enough...

bulkhead tightening.jpg
 
Peter Mizzi;2338150; said:
Hi guys I am currently setting up my 450gal It has two 25mm or 1 inch bulkheads in the rear of the tank , Are these going to be big enough to cope with 4500 LPH. :confused:

Any help would be greatly appreciated.

Regards

Peter
Click to expand...

part of the answer is as follows....

intake side do not exceed 5 ft/sec flow

returns from pump do not exceed 10 ft/sec


1 inch pipe has an area of pi*.5*.5=.79

5ft/sec is 60 inches per sec

.79*60=47.1 cu in sec

47.1 *60 = 2826 cu in min

231 cu in in a gallon

2826/231 = 12.2 gal min

12.2*60= 720 gph max per 1 inch id pipe
2728 l per hour per fitting max allowable flow

the rate you will get from gravity depends on the height of the falling water ( from top of water to bottom of pipe).

you may want to test the flow rate before committing to this size fitting


without testing use 1.5 or 2 inch



also silicone GREASE ( o ring grease) is good on the washer....dont over tighten...you can tighten more if need be...once the washer is squashed its over........
 
Thanks for all the help guys, I just went and picked up 2 x 40mm bulkheads instead of the 25mm, I tightened them about half a turn once finger tight.I just want to play it safe as I dont want to move the tank again once filled. The bulkheads are possitioned at the top of the tank about 20-30mm from the braces.There will be a 3.5 foot drop to the sump then a 4-5 foot return back to the tank.
 
You must log in or register to reply here.
MonsterFishKeepers.com
Top Bottom