DESIGN
FEATURES:
Precompression.
Precompressing the spring into the hanger casing
provides the following advantages:
(1) Saves up to 50% in headroom by reducing
the length of the hanger.
(2) Reduces the installed height of the
overall hanger assembly.
(3) Prevents the spring supporting force from
exceeding the normal safe limits of variation.
(4) Saves valuable erection
time because spring is precompressed to within
1/2 inch of the working range.
Available for protection against
severe weather conditions or corrosive conditions as
C-268, C-82 and C-98.
For moderate corrosive conditions
or severe weather, hanger is galvanized per ASTM
Specifications A-153 except the spring which is
neoprene coated to assure its flex life is not
affected. The load column of the type I hanger is
electro- galvanized.
For highly corrosive conditions,
hanger is completely neoprene coated except the load
column for type F which is stainless steel.
Not recommended where ambient temperatures exceed
225*F.
Load indicator is clearly seen in
the slot, simplifying reading of the scale plate.
Cold set at the factory upon request.
Spring and casing are fabricated
of steel and are rugged and compact.
Piston cap serves as a centering
device or guide maintaining spring alignment.
Casing protects the spring from
damage and weather conditions.
SPECIFICATIONS:
Grinnell pre-engineered spring hangers are designed to
meet the requirements of the ANSI Code for Pressure
Piping (ANSI B31.1.0). All welding is done in strict
accordance with the ANSI Code.
SIZE RANGE: The Grinnell
pre-engineered Variable Spring Hanger in three styles and
seven types is offered in twenty-three sizes (B-268 only
is offered in twenty-five sizes). The hanger can be
furnished to take loads from fifty pounds (B-268 from ten
pounds) to fifty thousand and ten pounds.
RECOMMENDED SERVICE: Pipe
hangers located at points that are subject to vertical
thermal movement and for which a constant support hanger
is not required (see "recommended service" for
constant support hanger, page 116).
APPROVALS: Complies with
Federal Specification WW-H-171 E (Types 51, 56 and 57)
and Manufacturers Standardization Society SP-69 (Types
51, 52 and 53).
INSTALLATION: Securely attach
hanger to the building. Attach lower hanger rod and turn
the load coupling until the load indicator is positioned
at the desired setting indicated on the load scale plate.
ADJUSTMENT OF HANGER: Once
installed in the line-, the hanger should be adjusted
until the load indicator moves to the white button marked
"C" (cold position). On inspection of the
system, after a reasonable period of operation, the load
indicator should be at the red button marked
"H" (hot position). If it is not, the hanger
should be readjusted to the hot position. No other
adjustment is necessary.
HOW TO DETERMINE SERIES: In
choosing between the B268, fig. 82 and fig. 98 variable
spring hangers, it must first be determined that the
calculated movement will fall within the working load
range of the hanger.
The fig. 82 hanger has a maximum
variation in supporting force per 1/2 inch spring
deflection of 21 percent of its rated capacity. The Fig.
B-268 has a maximum variation of 101/2 percent, while the
fig. 98 has a maximum variation of only 51/4 percent. It
is clear, then, that the longer spring causes the least
transfer of load, and that sheer ability to get the known
movement within the spring hanger's working range is not
the complete answer to the problem. Rather, good
engineering sense, combined with available space and
reasonable economic considerations should ultimately
determine which series of variable spring hangers should
be used.
DESIGN
FEATURES: