Brochure
Table Of Contents
Tunstall Corporation 
118 Exchange Street • Chicopee, MA 01013 
© July 2014 
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
The Macon MTW thermostatic operator will help you balance your heating system. The MTW operator 
has one of the most accurate sensors for individual radiator temperature control. The problem of over-
heating, under-heating and wide temperature swings can now be controlled. 
The MTW thermostatic operator by Macon Controls conserves energy by regulating temperature. Fuel 
costs can be reduced up to 30%! 
The MTW is a self-acting adjustable non-electric thermostatic operator. It has anti-freeze position, ad-
justable max./min. temperature, selected temperature locking feature and can be shutoff completely if 
required. Each MTW thermostatic operator is individually calibrated and conforms to ASHRAE stan-
dardization rules for temperature regulation. The MTW’s smooth shape and narrow air gaps gives a nice 
operation and makes it easy to keep clean. Can be mounted on all Macon NT series valves. Millions are 
in use throughout the world. 
See reverse for 
min/max field adjustment 
MTW shown with 
Macon NT series valve 










