Bullhead Tee's: Acceptable or not?

[TedLinsle]

I'm looking for some design guidance on when bullhead tee configurations are acceptable. I know they typically are to be avoided in hydronic systems, but don't see as much emphasis against them in domestic water & domestic water heating applications. My definition of a bullhead tee configuration is one that has flow into a branch tee from the branch connection. I don't know if it matters whether flow is incoming on one of the other connections, but it's definitely a bullhead when flow is both directions out of the non-branch connection.

 

[JohnBreen]

Bull head Tee's are defined as (Non-ANSI B16.9) Tee fittings where the "branch pipe" connection is of a larger diameter than the straight through "run" connections. Flow typically comes into the Tee via the "branch" pipe and the flow outlet is split between the two "run" connections. This is useful for supplying flow to smaller diameter piping in opposite directions without the need for reducers.

Foe example -

http://www.victaulic.com/docs/price/pl05fp.pdf

Bull head Tee's are appropriate for fire protection systems and for irrigation systems. They are not ideal for process piping for many reasons.

Regards, John.

 

[hydrae]

The availability of bull head tees is limited in sizes and materials, I have found that a plugged reducing cross will fit the bill which are standard fittings available for most applications.
Hydrae

 

[rconner]

I suspect at least small diameter bullhead tees may in general now be less available than more standard tees and crosses. I've noticed however some small diameter bulhead tee fittings may still be available (e.g. from Victaulic) and even some very large bullhead tees can still be manufactured by ACIPCO (see last table No. 6-10 at

http://www.acipco.com/adip/fittings/flanged/special.cfm).

I'm not exactly sure what would disqualify any such fittings from normal fluid flow applications; however, I suspect in most cases the reductions (on the run) are "concentric" and thus such would not be good for any connection/application requiring that the continuing piping etc. be "eccentric" with the top or invert of the run. Alternatives perhaps applicable in some cases are also full-opening tees, with concentric or eccentric reducers (when available) off the run ends.

 

[davefitz]

Plugged reducing crosses also help in terms of reducing the efects of erosion. The capped leg would typically have an anti-erosion incolnel plate taked in place with 3 weld spots.