Environmental Engineering Reference
In-Depth Information
Bell-and-spigot
Screwed (threaded)
Flanged
Welded
Soldered
figure 4.5 Common pipe joints.
section at one end of the pipe; the plain end is the
spigot
(see Figure
4.5). The spigot end is placed into the bell, and the joint is sealed. The
joint sealing compound is typically made up of lead
and oakum. Lead and oakum are the prevailing
joint sealers for sanitary systems. Bell-and-spigot
joints are usually reserved for sanitary sewer systems; they are no lon-
ger used in water systems.
Key Point:
Bell-and-spigot joints
are not used in ductile iron pipe.
4.8.5.3.2 Screwed or Threaded joints
Screwed or threaded joints (see Figure 4.5) are commonly used to
join sections of smaller diameter, low-pressure pipe; they are used in
low-cost, noncritical applications such as domestic water, industrial
cooling, and fire protection systems. Diameters of ferrous or nonferrous
pipe joined by threading range from 1/8 in. up to
8 in. Most couplings have threads on the inside
surface. The advantages of this type of connec-
tion are its relative simplicity, ease of instal-
lation (where disassembly and reassembly are
Key Point:
Maintenance supervisors
must ensure that screwed or threaded
joints are used within the limitations
imposed by the rules and require-
ments of the applicable code.
