Flowserve McCANNA McCannaflo Ball Valve User Manual

Mccanna/marpac valves, Mccannaflo, Ball valve

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McCANNA/MARPAC Valves

1. Installation

These valves may be installed in any position, and flow may be from
either direction. Special valves are marked to indicate special service
or flow direction. If valve has been furnished with means for body
cavity pressure relief, Installation Bulletin V-572 should be carefully
read before installation.

The hex end pieces (adaptors (15) are bottomed out in a very tight
metal to metal fit in factory assembly. This should prevent the
inadvertent loosening of the adaptors (15) when any normal piping
force is used in either direction. If it is necessary to back off piping to
line up equipment in new systems, it is still important to grip the
adaptor (15) next to the pipe being adjusted with a strap or parallel
jaw wrench. Do not use wrenches on the round body portion.

2. Stem Seal Adjustment

If leakage is evident in stem packing area, tighten the adjusting nut
1/4 turn. If leak still persists, repeat above. Replacement of stem seals
(10) is indicated if the leak is still apparent after 1/2 turn.

3. Disassembly

for Seal Replacement

–––––– W A R N I N G

———

A. Begin with the valve partially open in a depressurized line.

B. Hold the valve by the hexagonal adaptor (15) nearest to the pipe to be

disengaged. Unscrew the pipe from the adaptor (15).

IM V-576B

McCannaflo

®

Ball Valve

1/4"– 2" Threaded Ends

Installation, Operating and Maintenance Instructions

No.

Description

1

Handle

2

Stem

3

Stop Pins (2)

4

Handle Retainer Nut

5

Travel Stop

6

Gland Ring

7

Belleville Washer

8

Ball

9

Seats (2)

10

Stem Seal Set

11

Body

12

Adaptor Gaskets (2)

13

Grounding Washer

14

Adjusting Nut

15 Adaptors

(2)

FIGURE 1

A study of the sectioned drawings will reveal the simple construction of
McCannaflo threaded end ball valves. This line of valves has the “free
floating” ball principle. The ball is not fixed but is free to move with the
line pressure. As a result of this feature, these valves are capable of
tight shut-off with flow in either direction or dead-ended, regardless of

the position of the valve in the line. The downstream seat, which is
opposite the pressurized side of a closed valve must carry the load
exerted by the line pressure on the ball, while the upstream seat is
subject to little load or wear. For this reason it is sometimes possible to
increase useful seat life by turning the valve end-for-end in the pipe line.

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