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-DR-0714 
Valves 
DIFFERENTIAL PRESSURE VALVE 
DR 15
Setting the differential pressure 
Turn the valve spindle (see fig.) until it is wide open. 
Locate the maximum differential pressure of the pump 
on the vertical axis of the graph and draw a horizontal 
line to intersect the “n” line corresponding to the re-
quired flow rate according to the horizontal axis. 
Then turn the valve spindle clockwise the number of 
turns indicated by the selected “n” line. 
The DR 15 pressure relief valve is delivered with a 
spring for a differential pressure range of 0-2.9 PSI in 
place. To alter the range to 0-8.7 PSI, exchange the 
spring in the valve for the separate one delivered with 
it. 
Spring for 0.1-0.6 bar (10-60KPA) pressure range. 
Spring for 0-0.2 bar (0-20KPA) pressure range. 
KiloPASCALS - kPa x 0.1450 = pounds force per sq. inch. 
BARS - bar x 14.504 = pounds force per sq. inch. 
Reference numbers for ordering 
Art. No.  Code  Conn. No.  Thread 
4141501 DR 15  15  1/2” NPT 
Compression fittings must be ordered separately. 










