2
9A
12
11
2
9
6
4
5
10,10A
3
8
1
2A
15
15A
14
YARWAY SEATLESS BLOW-OFF VALVES
Type b and Type c
MAINTENANCE AND ADJUSTMENT
Packing ring adjusment
Yoke nuts (15A) should be tightened at regular
intervals. The yoke springs (14) will maintain a
constant load on the packing. Packing rings
will relax slightly during use and an adjustment
may be required. To adjust the packing,
back the plunger off slightly by turning the
handwheel (do not allow flow to occur) and then
tighten the yoke nuts. Approximately ¼ to ½
turn should be sufficient. Reseat the plunger
against the upper gland.
NOTE:
If the valve has not been operated for a long period, the
packing nuts should be adjusted prior to blowing down
the boiler.
Lubrication
A fitting (2A) is provided on the yoke for
lubricating the ball thrust bearing (11) and the
stem collar. This fitting is compatible with an
Alemite No. 7585 gun. A high temperature
grease equivalent to Texaco Regal AFB2
should be used to lubricate this area. Stem
threads should be kept well lubricated. A good
grade of antiseize compound similar to Never-
Seez NS165 should be used. Both of these
areas should be lubricated every six months.
Installation of packing rings
WARNING
This procedure should not be attempted unless all
pressure has been vented from the valve, and its
connecting lines, and the temperature of the valve
is at or near ambient.
Remove the stopscrew (10) then remove the
yoke nuts and springs. Turn the handwheel to
open the valve. This will raise the plunger. Turn
the handwheel to close the valve. This will raise
the yoke. Turn the yoke so that the holes and
studs are out of line and turn the handwheel to
open the valve. The plunger is thus withdrawn
from the valve.
Next, remove the glands and the old packing.
This can be done by using a Yarway gland and
packing puller or similar tool (Fig. 3) in the
following manner: Insert the tool until the
pawls engage the ports in the lower gland.
Tighten the nut on the top of the puller to draw
out the lower gland, upper packing and upper
gland. The lower packing can then be removed
using a hook tool. Care should be exercised,
however, so that the lower packing groove is
not damaged. Install new packing rings, (Fig. 4
or 5) glands and stopscrew in the body and
replace the yoke, with the plunger screwed all
the way up on the stem, in place and using the
yoke nuts pull down the yoke assembly. Next,
place the springs under the nuts and adjust as
previously described.
TYPE C ANGLE VALVE
Item Description
FIGURE 2
Type C angle valve
NOTE:
When ordering parts, use parts numbers and names
shown in table, specify size and type of valve, figure
number and operating pressure (see nameplate on
valve). Maintenance kits for Type B valves include
the following: cast iron valve, 250 psi: upper & lower
glands, packing set, springs, studs, nuts, stop screw,
stop screw gasket, cast steel valve, 300 psi & 400
psi: upper and lower glands, packing set, stem, ball
bearing, springs, studs, nuts, stop screw gasket.
1Body
2Yoke
2A Lubrication fitting
3Lower packing ring assembly
4Upper packing ring assembly
5Lower gland
6Upper gland
8Plunger assembly
9Stem
9A Stem nut
10 Stop screw
10A Stop screw gasket
11 Rail thrust bearing (2 Type C; 1 Type B)
12 Handwheel
13 Extension lever (Type C only)
14 Yoke springs (4 per set)
15 Yoke studs (4 per set)
15A Yoke stud nuts (4 per set)
