THE COLLIERY GUARDIAN.

247

January 31, 1913.

______________

“ SENTINEL” PATENT STOP VALVES

While they are stronger and more efficient than ordinary
stop valves, and while all the usual valve troubles
have been specially guarded against in their design,
"SENTINEL’ STOP VALVES

are actually cheaper than other patterns for similar pressures.
Moreover, a special type being provided for low pressures,
it is no longer necessary to go to the expense of a high-
pressure valve for pressures up to 125 lb. steam.

HERE ARE SOME OF THE TROUBLES FROM WHICH USERS OF
“SENTINEL” VALVES ARE FREE:

LOSS OF PRESSURE. The passages are practically
full area and the steam flows in easy curves.

LOOSE SEATING. The seating ring is screwed,
not merely forced into position.

EROSION. The steam is thrown clear of the internal-
valve faces by the chamfering of the seat.

CHATTERING. The internal valve receives pressure
from the spindle below the working face and cannot
rock or chatter.

WATER HAMMER. The cylindrical part of the
internal valve practically fits inside seating, and the first
turn of the handwheel allows but little steam to pass.

BINDING. The spindle, of nickel steel, has almost
the same coefficient of expansion as the chest and will
not bind when hot. The gland cannot bind on the
spindle, even if screwed down unevenly.

There are many other points of interest about

“SENTINEL” PATENT STOP VALVES

They and our other specialities for steam and water
users are fully described and illustrated in the catalogue
25 S, which will be sent on application.

ALWAYS USE & SPECIFY “SENTINEL” PATENT VALVES

V.JS68*

a

'-•“JP*.'.

,‘V<

- 4'Z l'

’ ' ■	V,> /.

>v>’

“Sentinel” Stop Valve

(Type for pressures to 125 lbs. steam)

Telegrams:
“Alley, Glasgow”

Alley & MacLellan

Limited

“Sentinel” Works

Polmadie, Glasgow

Telephone :
173 Queen’s Park

MESSRS. ALLEY & MACLELLAN, LTD., POLMADIE, GLASGOW.

Please send (™) a copy of your List 25 S.

Name -----------------------------------------------------______________________________________________________

Address_________________________________________________________

_________________________________________________
Ref. Cn.

__________________________________________________________________________