April 25, 1913.

THE COLLIERY GUARDIAN.

871

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“Sentinel” Patent
Stop Valves

Continuously Efficient

No. 201



Code Word : Apercibo

SPECIAL FEATURES

1.	Slight Loss of Pressure.—The pas-
sages are practically full area, and the flow
of steam being directed in easy curves
the loss of pressure is negligible.

2.	Strength.—The Chests are of best
Scotch iron, and their carefully rounded
shape gives them great strength. The

SCmNELWAYj



section at flanges is arranged as sketch,
thus avoiding the crystallization and weak-
ness inherent to the usual design.

3. Ample Packing Box.—The covers, too,
are of great strength, and are provided
with specially deep stuffing boxes which
require packing seldom.

4. Fool-Proof Gland.—The gland is of
special design, and

V. 15.59/

ttt

-Ml'I

No. 203

Code Word: Apercu

SPECIAL FEATURES

8. Erosion Prevented.—Chamfering the
seats combined with the

shape of the internal valve
throws the steam clear of
the faces. The projection
on valve throttles steam till
faces are clear.

9. Chattering Elimin-
ated.—The internal valve

receives pressure from the
spindle below the level of its working
face, and so does not chatter and bruise

SENTINLT WAM USUAL WAS!

does not bind on the
spindle as is usual if
unevenly tightened.

5.	Repacking under
steam may be effected
after opening the valve
wide (see section).

6.	No Loose Seats.—
The seating ring is of
hard Admiralty bronze.

It is screwed into the chest and cannot

loosen.

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Catalogue 25S, illustrating and giving
full particulars of these and other
“Sentinel” Valves for Steam and

7. Drained Seating.—We keep the work-
ing face well above condensation level,
and so the valve is tight, hot or cold,
wet or dry.

Wafer, will be sent on application.

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itself, which effect rapidly destroys ordinary
valves.

10.	Water Hammer is avoided by the
cylindrical part of the internal valve
practically fitting inside seating ring. The
first turn of hand-wheel lets but little
steam pass.

11.	Rotating Valve.—Every time it is
opened the internal valve rotates and finds
a new position, thus keeping the faces level.

12.	No Binding.—The spindle is of nickel
steel, having practically the same coefficient
of expansion as the chest, so that valves
shut cold do not bind when hot, as is usual.
The spindle, too, is about three times as
strong as bronze spindles usually fitted,
which we will supply if required without
extra charge.

For satisfaction always use and specify “Sentinel ” Valves

ALLEY & MACLELLAN, LTD

MAKERS OF VALVES — AIR COMPRESSORS — AND MOTOR WAGGONS

elegrams

“Alley, Glasgow”

“Sentinel” Works

Polmadie, Glasgow

el ephone

173 Queen’s Park

Messrs. Alley & MacLellan, Limited, Polmadie, Glasgow
Please send (£) a copy of your Catalogue 25 S.

N ame____________________________—----------------------------------------------------------.--------

Address____________________________________________________________________

Ref. Gn._________________________________________________________________________