Product Overview

INDIRECT FIRED
Valves designed to operate on indirect red atmospheric
burner applications M420, M520, M620.
These valves function in the same manner as the direct red M
valves. A pressure adjustment spring has been factory set to
obtainanoutletpressureslightlyaboveatmosphericpressure(0.1”
w.c.) with the bypass closed and zero voltage being applied. The
minimumowrateisnowadjustedthroughthebypass.
NOTE:Minimumoutletpressureisalwaysabove0.2”w.c.
Maximumoutletpressureis7.0”w.c.
The valves are driven by the A1094 and AD1094 Ampliers or
SC11 Signal Conditioners. (Refer to Bulletin SEL94_CC_EN &
SC11_MS_EN.)
Valves designed to operate on indirect red atmospheric
burner applications M451, M551, M651, MR251D, MR251E,
MR251G.
These valves function in the same manner as the direct red M
valves.Minimuminputpressureissetusingaminimumadjustment
spring - the valves do not use a bypass.
They are used in applications where the minimum input pressure
toburnerisbetween2.0”and4.5”w.c.Maximumobtainableoutlet
pressureis7.0”w.c.aboveminimuminputpressure.
The valves are driven by the A1094 and AD1094 Ampliers or
SC11 Signal Conditioners. (Refer to Bulletin SEL94_CC_EN &
SC11_MS_EN.)
MR410, MR510, and MR610
These valves use two springs in order to set the high and low
re settings. One spring (min.) surrounds the solenoid and is
always in contact with the diaphragm assembly. The other spring
(max.) is located above the plunger. With zero voltage applied, the
minimum and maximum spring’s down force, along with plunger
weight, pushes down on the diaphragm thereby setting a regulated
highre.Aseparatepressureregulatorisnotrequired.Asvoltage
isapplied,theplungerpullsupsufcientlyuntilallplungerweight
and maximum spring force is removed. The pressure is now
controlled with the minimum spring setting giving a regulated low
recondition.Forceontheplungerbetweentheextremesresults
inmodulatedgasow.Thevoltage versus outlet pressure curve,
throughout the modulating range, is not linear.
These valves are driven with the A1010 or A1011 Amplier or
SC11 Signal Conditioners. (Refer to Bulletin SEL2030_2131_CC_
EN & SC11_MS_EN)
‘H’ SUFFIX MODELS
Valves designed with wider modulation span for use with
LP (liquid propane gas) and other applications MR410H-1,
MR510H-1, MR610H-1, M420H, M520H, M620H.
Can be congured for indirect red atmospheric burner
applications,aswellasthosewithdirectredburners.
‘H’ models are designed for applications where outlet pressure is
greaterthan7”w.c.Minimumoutletpressureisfactorysetto1.75”
w.c. - remaining set pressure is obtained through bypass. The ‘H’
modelsarecapableofatotalmodulationspanofasmuchas10”
w.c. These models are not recommended for applications with a
totalmodulationspanoflessthan7”w.c.-thesensitivityofoutlet
pressure change relative to voltage change could cause hunting
to occur.
‘H-1’ models are designed for applications with a total modulation
spangreaterthan7”w.c.Minimumoutletpressurerangeof1”to
2.8”w.c.
NOTE: Temperatures shown in text are for Maxitrol’s Selectra
®
systems. Valves may be used for any temperature range
or application the user’s controller can handle. When
using valves for other ranges, a Maxitrol SC11 Signal
Conditioner can be used in conjunction with the valve.
(Refer to Bulletin SC11_MS_EN)
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M/MR Series Literature