Rubber, plastic, or unthreaded type of protective
closures of metal construction conforming to specifica-
closures designed to fit over open ends of bulk hose and
tions listed in table 8-4 for sealing hydraulic system
tubing should be used in accordance with design
equipment, lines, tubes, accessories and components.
function only. Do not use this type of protective closure
Figure 8-21 shows typical blank-off plates. In all
as a plug for insertion into open lines, hoses, or ports of
cases where there is a choice between an internal or
hydraulic equipment. Remove protective closures
external installation, use the external type of closure.
before installing equipment. If an opening normally
Use metal protective closures to seal open ports of all
requiring protection is found uncovered, the part or
hydraulic lines and accessories. Use metal protective
assembly should be cleaned and checked before
closures to seal new and reusable hydraulic tubing and
installation or assembly.
hose assemblies. Plastic closures may be used to seal
Q8-23.
What component is used to provide a means
electrical fittings and receptacles or other nonfluid
of quickly disconnecting a line without the
openings where contamination is not considered a
loss of hydraulic fluid?
problem. Keep all protective closures clean, sorted by
size, properly identified, and stored in readily
Q8-24.
When the quick-disconnect coupling is
accessible bins. Check protective closures visually for
disconnected, what component prevents the
cleanliness, thread damage, or sealing deformation
loss of fluid and entrance of air?
before using.
Table 8-4.--Protective Caps and Plugs
TYPE
APPLICATION
APPLICABLE
SPECIFICATION
Cap
Flared Fitting
MIL-C-5501 (Preferred) or
NAS 817
Cap
Beaded Hose Connection
MIL-C-5501
Cap
Pipe Thread
MIL-C-5501
Cap
Assembly, Pressure Seal Flared Tube Fitting
AN929
Cap
Pressure Seal, Flareless Tube Fitting
MS21914
Plug
Flared Tube End and Straight Threaded Boss
MIL-C-5501 (Preferred) or
NAS-818 or AN806
Plug
Flareless Tube End
MIL-C-5501 (Preferred) or
MS21913
Plug
Flared Tube Precision Type
MS24404
Plug
Pipe Thread
MIL-C-5501
Plug
Bleeder, Screw Thread
AN814
Plug
Machine Thread O-Ring Seal
MS9015
Plug
Machine Thread AMS 5646 Preformed Packing
MS9404
Plug
Bleeder, Screw Thread Precision Type
MS24391
NOTE:
1. When ordering from supply, be sure to specify metal caps or plugs.
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