Types N480 and N481
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the purchaser.
Emerson Process Management
Fisher Controls International, LLC.
P.O. Box 8004
McKinney, Texas 75070, USA
Telephone: 1 (800) 588-5853
Telephone: 1 (469) 293-4201
©Fisher Controls International, LLC., 1981; All Rights Reserved
Type N480 has a brass accessory back check
(Type M570) that can be tightened back onto filler valves
that fail to close. Then the N480 main valve can be
loosened from the back check. If the pressure bleeds
off between the N480 and the M570, the M570 can be
left on the filler valve until repairs can be made, and the
N480 main valve can be disconnected. Leave the M570
on a filler valve only until the tank can be emptied and
repair or replacement of the filler valve can be made.
If pressure does not bleed off between the N480 and
M570, there is still a problem. Do not disconnect until
the problem is corrected and the valves seal tightly. Try
quickly opening and closing the N480 or tapping the
sides of the valves to seat the check valves.
Should it be necessary to detach the M570 and leave
it on a ftiler valve, fit a new M570 to the N480 as soon
as possible.
Do not use any model of back check
assembly other than the M570 because other models
could allow accidental opening of the N480 when
being carried.
Maintenance
Check the hose end valve periodically for signs of wear
or mechanical damage. The operating lever and linkages
should be kept free of obstructions. The surface of the
flow tube which seals against the filler valve’s gasket
should be kept free of large nicks. Check the coupler
for wear. If repair becomes necessary, contact a Fisher
distributor or the factory for information and assistance.
Do not use valves that leak or fail to operate correctly;
repairs should be made promptly.
Parts List
Key Part Name
1
Body
2
Yoke (2 required)
3
Coupler
4
Handle
5
Dowel Pin
6
Guide
7
O-Ring
8
X-Ring
9
Flow Tube
10 Disc Holder
11 Disc
12 Washer
13 Flat Spring
Figure 2.
Type N480
Key Part Name
14 Spring
15 Linkage (2 required)
16 Snap Ring
17 Rivet (2 required)
18 Set Screw (2 required)
19 Apply Loctite No. 262
20 Apply Loctite No. 242
21 Apply Magnalube-G
22 Type M470
18
20
4
1
14
10
20
7
12
8
21
5
19
11
2
16
13
6
3
9
22
SECTION: A ~ A
A
A
