Note
It is important that the regulator be 
installed so that the vent hole in the 
spring case is unobstructed at all times. 
For outdoor installations, the regulator 
should be located away from vehicular 
traffic and positioned so that water, ice 
and other foreign materials cannot enter 
the spring case through the vent. Avoid 
placing the regulator beneath eaves or 
downspouts, and be sure it is above the 
probable snow level.
Overpressure Protection
The recommended pressure limitations are 
stamped on the regulator nameplate. Some type of 
overpressure protection is needed if the actual inlet 
pressure exceeds the maximum operating outlet 
pressure rating. Overpressure protection should 
also be provided if the regulator inlet pressure 
is greater than the safe working pressure of the 
downstream equipment.
Regulator operation below the maximum pressure 
limitations does not preclude the possibility of damage 
from external sources or debris in the line. The 
regulator should be inspected for damage after any 
overpressure condition.
Startup
The regulator is factory set at approximately 
the midpoint of the spring range or the pressure 
requested, so an initial adjustment may be required 
to give the desired results. With proper installation 
completed and relief valves properly adjusted, slowly 
open the upstream and downstream shutoff valves.
Adjustment
To change the outlet pressure, remove the closing 
cap or loosen the locknut and turn the adjusting 
screw clockwise to increase outlet pressure or 
counterclockwise to decrease pressure. Monitor 
the outlet pressure with a test gauge during the 
adjustment. Replace the closing cap or tighten the 
locknut to maintain the desired setting.
Taking Out of Service (Shutdown)
!
WARNING
To avoid personal injury resulting from 
sudden release of pressure, isolate 
the regulator from all pressure before 
attempting disassembly.
Parts List
Types 6492L and 6492H
Key Description
1 Body
2  Valve Guide
3  Valve Spring
4*  Inner Valve
5* Orice
7*  Valve Stem
8*  Bellows Retainer
9* Bellows
10* Diaphragm
11  Lower Spring Seat, Types 6492H and 6492HT Pilots only
12  Control Spring
13  Upper Spring Seat
14  Spring Case
15  Adjusting Screw, standard spring case only
16  Hex Nut, standard spring case only
17  Cap Screw
18*  Diaphragm Gasket
19  Drive Screw
20 Nameplate
24  Diaphragm Plate Assembly, Type 6492L Pilot only
74  Pipe Plug
76  Bleed Restriction
77 Screen
78  Reducing Bushing
87  Sealing Washer, tapped spring case only
TYPE
MAXIMUM ALLOWABLE INLET PRESSURE
MAXIMUM OPERATING  
OUTLET PRESSURE
MAXIMUM EMERGENCY OUTLET PRESSURE
Cast Iron Steel/Stainless Steel
bar psig bar psig bar psig Cast Iron Body Steel/Stainless Steel Body
6492HT - - - - - - - - 20.7 300 17.2 250 - - - -
20.7 bar / 300 psig or main 
valve body rating limit, 
whichever is lower
6492H 17.2 250 20.7 300 10.3 150
17.2 bar / 250 psig or main 
valve body rating limit, 
whichever is lower
20.7 bar / 300 psig or main 
valve body rating limit, 
whichever is lower
6492L 17.2 250 20.7 300 1.7 25 6.9 bar / 100 psig 6.9 bar / 100 psig
Table 2. Maximum Inlet and Outlet Pressures
*Recommended spare part.
Type 6492
2