Brochure

© 2015, Maxitrol Company. All Rights Reserved.
DRAFT 09.18.2013
58
When sizing a regulator the following must be known:
• Gas Type
• Available Inlet Pressure
• Desired Outlet Pressure
• Zero Governor Application (indicated by model number ending in “Z”)
• Will the regulator control main burner and pilot load OR main burner only?
• Required minimum and maximum ow rate in cfh or m
3
/h or Btu/h
• Pipe Size
In most cases, the manifold pipe size has already been selected on the basis of good engineering practice, and the regulator
pipe size should conform to this size.
The capacity of any regulator is not an absolute value but will vary with the application depending on the prevailing differential
pressure.
Service and installation must be performed by a trained/experienced service technician.
All products used with combustible gas must be installed and used strictly in accordance with the instructions of the Original
Equipment Manufacturer (OEM) and with all applicable government codes and regulations, e.g. plumbing, mechanical, and
electrical codes and practices. These instructions do NOT supersede OEM’s installation or operating instructions.
All Maxitrol products should be installed and operated in accordance with Maxitrol Safety Warning Instructions.
HOW TO CALCULATE PRESSURE DROP AT VARIOUS FLOW RATES FROM CAPACITY CHART
LP Applications - When using natural gas pressure drop chart to determine LP pressure drop in terms of Btu/h, multiply LP
Btu/h by 0.621; in terms of CFH multiply LP CFH by 1.55.
Formula: P2 = P1 x (Q2/Q1)
2
P2 = Pressure drop at desired ow rate Q2 = Desired ow rate
P1 = Known pressure drop Q1 = Known ow rate
A. Check Capacity Chart, insuring regulator has ample range B. Know the minimum encountered inlet pressure.
of regulation and individual load capacities (for use with pilot) MINIMUM INLET PRESSURE MINUS “P2” MUST
for the application. BE GREATER THAN DESIRED OUTLET PRESSURE.
Solve for “P2” using the formula above.
(See examples on page 59.)
SIZING A REGULATOR
System Requirements
See www.maxitrol.com for our Regulator Sizing Program. Please contact Maxitrol directly for more information on sizing a regulator.