February 28, 1913.

THE COLLIERY GUARDIAN.

455

EXAMINE THE CONSTRUCTION

of a “ Sentinel ” Patent Stop Valve, and you will be able to appreciate
some of its points of superiority over ordinary valves.

(LThe seat is chamfered and the shape
of the internal valve is such that steam
is thrown clear of the face.

This prevents Erosion.

CLThe cylindrical part of the internal
valve practically fits inside the seating
ring, and the first turn of the hand-
wheel allows but little steam to pass.
This avoids Water-hammer.

(LThe pressure of the spindle is exer-
cised below the working face of the
internal valve.

This eliminates Chattering.

<LThe internal valve rotates each time
it is opened.

This keeps the faces level.



CLThese are only a few of the points of superiority of “Sentinel” Patent
Valves. Others, including its exceptional strength, its non-binding
spindle and its fool-proof gland are fully described and illustrated in
Catalogue 25S, sent free to responsible engineers and others on
application.

__________________________________________

Always use and specify “SENTINEL” PATENT VALVES

Alley & MacLellan, Ltd

Sentinel Works, Polmadie

Telegrams
ALLEY, GLASGOW

Glasgow

Telephone
173 QUEEN’S PARK

..............................

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

Name_____________________________________________________

Address_____________________________________

Ref. Cn.