8
T
B .001
-B-
.001
A .001 TIR
T
B .001
/ / -B- .001
.001
1.5°
3°
45°
F -3( ), -4( )
3.826
97.181
G -3( ), -4( )
3.807
96.703
H -3( ), -4( )
4.160
105.664
J -3( ), -4( )
4.230
107.442
K -3( ), -4( )
4.762
120.955
L -3( ), -4( )
5.153
130.892
M -3( ), -4( )
5.934
150.724
N -3( )
5.807
147.496
N -4( )
6.240
158.496
P -3( )
6.039
153.391
P -4( )
6.275
159.385
Q -3( )
8.082
205.283
Q -4( )
8.515
216.281
CROSBY
STYLE HSL SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
Minimum face-to-seat
dimension,
see Table 2
.014 0.356
.010 0.254 Mach.
.004 [.102] Min.
after lapping
.014 0.356
.010 0.254 Mach.
.008 [.203] Min.
after lapping
FIGURE 5
TABLE 2 - MINIMUM NOZZLE FACE TO SEAT
DIMENSIONS
Orifice and series
Dimensions
NPS
DN
H. Remove the guide and guide ring from the
body as an assembly and unscrew the guide
ring from the guide.
I. If the valve has a 2-piece disc holder,
remove the disc insert cotter pin and the
disc insert from the disc holder assembly.
J. Remove the spindle from the disc holder
assembly or disc by pulling up on the
spindle rod to engage the spindle point
threads in the disc holder. Turn the spindle
counterclockwise while holding the disc/
holder still and remove the spindle rod.
K. Unscrew the nozzle ring from the nozzle.
L. Unscrew the nozzle from the body (the
Crosby Style HSL utilizes a removable full
nozzle design).
Inspection and refurbishment
All the parts should be cleaned thoroughly.
Guiding surfaces may be polished using a fine
emery cloth. All parts should be examined to
determine their condition. Inspection of valve
components is important to ensure proper valve
performance.
Measure the nozzle height using Table 2 and
Figure 5. If the nozzle measures below the
minimum dimension it should be replaced. Discs
and disc inserts should be measured using
Table 3 and Figure 8. Parts not meeting these
dimensions should be replaced.
Spindles should be inspected to ensure they are
straight using the TIR values found in Table 4.
Use either V-blocks or chuck the spindle into a
lathe and dial indicate to check for straightness.
If necessary, the spindle may be straightened
by applying force to the spindle until within
tolerances. If it is not possible to straighten a
bent spindle, it should be replaced.
Lapping valve nozzles and disc inserts
Good seating surfaces on the nozzle and disc
insert are necessary for the valve to seal tightly
when the valve is in the closed position. The HSL
is a metal seated valve and the sealing surfaces
of the nozzle and insert may be lapped to ensure
a flat surface free from scratches and other
imperfections. The sealing surface of the nozzle
may be machined to remove deeper scratches
or damage to the nozzle as long as the nozzle
height exceeds the minimum dimensions (after
machining) as shown in Table 2.
In the following sections you find information
on lapping techniques, tools and materials.
Lapping blocks are made of a special grade of
annealed cast iron (see Figure 6). There is a
block for each orifice size. Each block has two
perfectly flat working sides and it is essential
that they retain this high degree of flatness to
produce a truly flat seating surface on the disc,
or disc insert and/or the nozzle.
Before a lapping block is used, it should be
checked for flatness and reconditioned after
use on a lapping block resurfacing plate. The
block should be lapped in a figure eight motion,
applying uniform pressure while rotating the
lapping block against the plate as shown in
Figure 7.
Lapping blocks and lapping block resurfacing
plates are available from Emerson sales,
service and distribution centers.
Experience has proven that medium coarse,
medium, fine and polish lapping compounds
will condition any damaged safety valve seat
properly except where the damage requires
machining.
The following lapping compounds, or their
commercial equivalents are suggested:
LAPPING COMPOUNDS TABLE
Grit compound no.
Description
320
Medium coarse
400
Medium
600
Fine
900
Polish
