Brochure
Table Of Contents
ONE-PIPE STEAM VALVE ASSEMBLY
OPSK
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-OPSK-0714 
Non-Electric Operators 
Example 
Macon MTW 
Direct Thermostatic Operator 
Vent 
Vacuum Breaker 
Valve Body 
DATA - One-pipe Steam Valve Assembly 
Maximum temperature: 248°F 
Disc Material:  EPDM 
Valve body material:  Forged, nickel-plated brass 
Body style:  Angle pattern 
Connections:   1/8" male NPT, fits in vent tapping of 
 the radiator 
Temperature range:  46°-82°F 
Maximum movement:  .125 (3mm) 
Movement per 1°F change in ambient: .007 (.15mm) 
Note: Additional information and installation instructions 
can be found in Technical & Service Section. 
Dial Setting 
Room 
Temperature 
(F) 
0 Off 
* 46º 
1 54º 
3 61º 
5 68º 
6 72º 
7 76º 
8 80º 
9 82º 










