What is a boss fitting

Status
Not open for further replies.

robh

Member
Boss fittings

Boss fittings

The boss fittings I know of are for hydraulic applications.

oringboss.jpg

From our friends at Wiki:
An o-ring boss seal is a technique for joining two fluid-carrying pipes, hoses, or tubing. In an o-ring boss (abbreviated ORB) system, a male-threaded part is inserted into a female-threaded part, providing a mechanical seal. This system differs from others in that an additional nut is tightened over an o-ring into a chamfered area, creating a fluid-tight seal.
This system is used most frequently in hydraulics, although it has been applied to other systems including compressed air systems and vacuum pumps, such as many Robinair pumps, in which the intake tee has an o-ring boss seal on the bottom. The ORB system can be confused with other connection systems, such as NPT. While threads of different connectors sometimes fit (although often very inexactly), o-ring boss seal system connectors should never be used with any other type of connectors and vice versa, as leaks are likely. Under the high fluid pressures commonly seen in hydraulic systems, a leak or failure of the connection is quite dangerous and could lead to loss of life.

This system has the advantage of being able to be tightened mechanically before being sealed. Most threaded systems, such as NPT, have a seal provided by a taper in the thread, so it is difficult to orient both ends of the hose, pipe or tube so that it is not twisted. In the o-ring boss system, this problem is eliminated because the threads do not seal the connection and therefore can be rotated at least a full revolution before they are sealed while maintaining a proper mechanical connection. The orientation problem could also be solved with a suitable union.
 

Smart $

Esteemed Member
Location
Ohio
Ive never heard the term before.
Typical conduit connectors are boss fittings. "Boss" as used in this sense is a generalization meaning there is an enlarged body part which prevents complete passage through a smaller-sized hole; a shoulder around the body.
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Basically, an electrical enclosure or fitting with a "boss" has integral threads, usually five or more. A typical conduit body or FS box are boss type. It must be an integral part of the enclosure; i.e., a hub fitting would not make a Type 12 enclosure a boss enclosure.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Basically, an electrical enclosure or fitting with a "boss" has integral threads, usually five or more. A typical conduit body or FS box are boss type. It must be an integral part of the enclosure; i.e., a hub fitting would not make a Type 12 enclosure a boss enclosure.
That sounds like an electrical example of a more general situation in which a "boss" is a lump of metal, often with a threaded hole, which is brazed or welded to a tube or other structural member so that something can be mechanically attached without reducing the integrity of the member by drilling a hole in it.
In some cases (like a cast member) the boss will be an integral part of the member itself, with the machining to add the threads done later. That fits with your example of a thickened section of the conduit body to allow a greater number of threads in the hole.
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
Boss is indeed a general term defined in Webster's Eleventh Collegiate Dictionary as:
1boss
noun \ˈb?s, ˈbȯs\
Definition of BOSS
1
a : a protuberant part or body <a boss of granite> <a boss on an animal's horn>
b : a raised ornamentation : stud
c : an ornamental projecting block used in architecture
My own experience with the term electrically comes from Section 502.10(A)(1)(4).There is another more general reference in Section 300.4(G) Exception which I never personally refer to but it is there.
 
Last edited:

ritelec

Senior Member
Location
Jersey
Typical conduit connectors are boss fittings. "Boss" as used in this sense is a generalization meaning there is an enlarged body part which prevents complete passage through a smaller-sized hole; a shoulder around the body.

I gotta get my mind out of the gutter

:happyyes:
 

Smart $

Esteemed Member
Location
Ohio
Boss is indeed a general term defined in Webster's Eleventh Collegiate Dictionary as:
My own experience with the term electrically comes from Section 502.10(A)(1)(4).There is another more general reference in Section 300.4(G) Exception which I never personally refer to but it is there.
While I agree with your comments, the OP is regarding a "boss fitting", which enclosures, boxes, and conduit bodies, or parts thereof, are not... ;)
 

chrisjacob

Member
Location
India
boss fitting

boss fitting

Dont worry. I have also not heard it before. One of my friend provides plumbing services he told me about boss fitting. There are fitting tools are available like Boss Clamp 2 Bolt,Boss Ground Joint Double Spud,Boss Hose Mender,Boss Holedall Fitting. You can consult with professional plumber which provides plumbing services.
 

Smart $

Esteemed Member
Location
Ohio
Dont worry. I have also not heard it before. One of my friend provides plumbing services he told me about boss fitting. There are fitting tools are available like Boss Clamp 2 Bolt,Boss Ground Joint Double Spud,Boss Hose Mender,Boss Holedall Fitting. You can consult with professional plumber which provides plumbing services.
Assuming the OP is regarding an electrical fitting, plumbing (or pipefitter) terminology does not apply ;)
 
Status
Not open for further replies.
Top