Brochure
Table Of Contents
Tunstall Corporation 
118 Exchange Street • Chicopee, MA 01013 
We reserve the right to alter designs, specifications and information without notice. 
Phone (413) 594-8695 · Fax (413) 598-8109 
www.tunstall-inc.com • www.maconcontrols.com 
Bulletin-MTW-0714 
Non-Electric Operators 
THERMOSTATIC OPERATOR 
DIRECT MOUNT 
MTW
DIRECT 
MOUNT 
DIRECTION 
OF FLOW 
DIRECT MOUNT THERMOSTAT 
MOUNTED THRU FACE OF COVER 
PIPE COLLAR 
(NOT SUPPLIED) 
Maximum & Minimum Setting 
Maximum setting 
1.  Turn the wheel to maximum and a red mark 
will occur in the indicating window (located 
opposite the dial setting window). 
2.  Push the mark in while turning the wheel to 
desired temperature according to below chart. 
3.  When reached desired temperature let go of 
the mark and the maximum temperature limit 
is set. 
Minimum setting 
1.  Turn the wheel to minimum and a blue mark 
will occur in the indicating window (located 
opposite the dial setting window). 
2.  Push the mark in while turning the wheel to 
desired temperature according to below chart. 
3.  When reached desired temperature let go of 
the mark and the minimum temperature limit 
is set. 
DATA 
Temp. Range: 46° - 82°F 
Hysteresis: 0.9°F 
Heat Transfer: 1.1°F (Valve Housing Sensor) 
Dead Time: 0.8 Minutes 
Max. Differential Pressure: 20 psi 
Suggested Differential Pressure = 0.5 to 2.9 psi 
Max. Water Temp.: 250°F 
Max. Storage & Ambient Temp.: 122°F 
Max. Steam Pressure: 15 psig 
Max. Movement: 0.125 
Nominal Opening: 0.018 (3.6°F) 
Long Term Test: 5000 cycles (1.3°F) 
DIAL SETTINGS: 
0 = Off 
* = 46°F (Frost Protection) 
1 = 54°F 
3 = 61°F 
5 = 68°F 
6 = 72°F 
7 = 76°F 
8 = 80°F 
9 = 82°F 










