reduced ID fittings
reduced ID fittings
(OP)
We ordered standard B16.9 fittings but some of them came with a reduced ID. For example, an 8" - Schedule 160 tee. The nominal ID that we expected would be 6.813". What was supplied was a tee with an ID of 4.96". We did not find this out intil system flow testing. We were not getting the flow that our hydraulic modeling predicted. The tee was UTed and subsequently cut out. My question is what should we have specified in order to get a tee with the expected ID?
thanks
Mark
thanks
Mark





RE: reduced ID fittings
Honestly, I don't know if there's an industry standard in any industry for specifying what you want, except maybe to add language to the PO that a ball of a given size has to fall through the lumen.
Mike Halloran
Pembroke Pines, FL, USA
RE: reduced ID fittings
Surprisingly B 16.9 6.2.2 says "6.2.2 Bore Diameter. Bore diameters away from the ends are not specified. If special flow path requirements are needed, the bore dimensions shall be specified by the purchaser."
So do exactly that - " 8" schedule 160 tee with minimum main bore of 6.8" diameter "
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: reduced ID fittings
RE: reduced ID fittings
RE: reduced ID fittings
RE: reduced ID fittings
RE: reduced ID fittings
What you would want to spec the supplier is typically called a "through bore" fitting which you would then get you what you should expect. In addition I'd probably ask for fabrication drawings to approve as in some cases the outer dimensions are changed to meet this criteria.
RE: reduced ID fittings
ISTR that most of the system was nominally 3" PVC, but somewhere in the middle of it the builder had installed a fitting called a "king nipple" that was found to have a bore under 1.5" diameter. That limited the flow, and in turn the exhaust system cooling, which is how it became my problem. It took a week of phone calls back and forth, and actual attempts to roll a ball through the system a section at a time to discover the root cause.
I never did get a ride on the yacht, but we got the system working okay with a bigger nipple, so it was a happy ending.
Mike Halloran
Pembroke Pines, FL, USA