Velocity Mega-Stor II User manual

VELOCITY LOGO CMYK COLORS
Mega-Stor®II
Stainless Steel, Buffer Tanks
INSTALLATION AND OPERATING INSTRUCTIONS
Velocity Boiler Works, LLC
P.O. Box 14818
3633 I Street
Philadelphia, PA 19134
www.velocityboilerworks.com
980109 - 3/19

2

1
IMPORTANT INFORMATION - READ CAREFULLY
NOTE: The equipment shall be installed in accordance with those installation regulations enforced in the area where the
installation is to be made. These regulations shall be carefully followed in all cases. Authorities having jurisdiction
shall be consulted before installations are made.
The following terms are used throughout this manual to bring attention to the presence of hazards of various risk levels,
or to important information concerning product life.
DANGER
Indicates an imminently hazardous situation
which, if not avoided, will result in death, serious
injury or substantial property damage.
CAUTION
Indicates a potentially hazardous situation
which, if not avoided, may result in moderate or
minor injury or property damage.
WARNING
Indicates a potentially hazardous situation
which, if not avoided, could result in death,
serious injury or substantial property damage.
NOTICE
Indicates special instructions on installation,
operation, or maintenance which are important
but not related to personal injury hazards.
WARNING
Improper installation, adjustment, alteration, service or maintenance can cause property damage,
personal injury or loss of life. Read and understand the entire manual before attempting installation,
start-up operation, or service. Installation and service must be performed only by an experienced,
skilled, and knowledgeable installer or service agency.
Burn Hazard. This tank contains very hot water under high pressure. Do not unscrew any pipe ttings
nor attempt to disconnect any components without positively assuring the water is cool and has no
pressure. Always wear protective clothing and equipment when installing, starting up or servicing this
product to prevent scald injuries. Do not rely on the pressure or temperature gauges to determine the
temperature and pressure of the water heater. Portions of this tank and connected piping become
very hot while operating. Do not touch any components unless they are cool.
Failure to follow all instructions in the proper order can cause personal injury or death. Read all
instructions, including all those contained in component manufacturers manuals which are provided
before installing, starting up, operating, maintaining or servicing.
FOLLOW ALL INSTRUCTIONS and warnings
printed in this manual and posted on the indirect
water heater.
IF YOU ARE NOT QUALIFIED to install or service
heating equipment, do not install or service this
one.
THIS TANK MAY LEAK WATER at the end of its
useful life. Be sure to protect walls, carpets, and
valuables from water that could leak from the tank.
PROTECT YOUR HOME IN FREEZING
WEATHER. A power outage, safety lockout, or
component failure will prevent your boiler from
lighting. In winter, your pipes or this tank may
freeze and cause extensive property damage. Do
not leave the heating system unattended during
cold weather unless alarms or other safeguards
are in place to prevent such damage.
WARNINGS FOR THE HOMEOWNER

2
CONTENTS
I. Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
 II. Specications........................................3
III. Before Starting Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
 IV. BuerTankApplication................................5
 V. LocatingTheBuerTank...............................6
VI. Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
VII. Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

3
I. PRODUCT DESCRIPTION
Thisbuertankisdesignedforinstallationinaclosedlowpressurehotwaterspaceheatingsystemwhereithastwoprinciple
purposes:
  • Hydraulicseparation–Wheninstalledasspecied,theowratethroughtheboilerloopwillbeessentially 
   independentofthatthroughtheheatingsystem.Thisisparticularlybenecialwhentheboilerrequiresaminimum
   owratewhichishigherthanthatthoughthesystematlowerheatingdemands(e.g.whenonlyonesmallzoneis
calling for heat).
  • Reductioninburnercycling–Thistankaddsmasstothesystemwhichresultsinlongerburneroncyclesifthetank
is applied properly.
Becauseofthelowvelocitiesinthetank,thebuertankalsoservesasanexcellentairseparator.
II. SPECIFICATIONS
FIGURE 2.1: MEGA-STOR II BUFFER TANK
MSB030THRUMSB075
WARNING
This bu󰀨er tank is for use in low pressure hydronic systems only:
• Do not use in potable water systems.
• Do not operate above the temperature and pressure ratings shown on the rating plate.

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Description Model
MSB030-MSB075
Boiler Supply/Return 1-1/2”F
System Supply/Return 1-1/2”F
Top(AirVent) 1”F
Drain 3/4”F
TABLE 2.3: CONNECTION SIZE (in. NPT)
Model Volume
(Gal.)
Dimensions in Inches Weight
A B C D E Net Full
MSB030 31.4 33-1/8 20-7/8 16-1/8 11-1/4 6-1/8 71 333
MSB050 52.6 49-3/4 37-5/8 24-1/2 11-1/4 6-1/8 82 520
MSB075 76.3 68-3/4 56-1/2 33-7/8 11-1/4 6-1/8 115 751
TABLE 2.2: PHYSICAL SPECIFICATIONS
III. BEFORE STARTING INSTALLATION
1) Be sure that the planned installation is in accordance with all local codes.
 2)Becertainthewatersupplyusedtollthehydronicsystemhasphysicalandchemicalcharacteristicsthatfallwithinlimits
     s h o w n  b e l o w .  W h e r e  q u e s t i o n s  e x i s t  a s  t o  t h e  c o m p o s i t i o n  o f  t h e  w a t e r  o n  t h e  j o b ,  a  q u a l i  e d  w a t e r  t r e a t m e n t  e x p e r t           
should be consulted.
3) Read and understand all application and installation requirements in this manual.
CAUTION
Water used in this indirect water heater must have characteristics falling within the following limits:
PH 6.0 – 8.0
Chloride Content – Less than 80PPM
Water failing to meet these requirements may severely shorten the life of this product due to
corrosion. Such corrosion damage is not covered by the warranty.

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IV. BUFFER TANK APPLICATION
A) SIZING
 Buertanksaresizedusingthefollowingequation:
Where:
  V=Requiredtotalvolume(inGallons)forthebuertank,boiler,boilerlooppiping,andanysystemlooppipingthat
  willalwayshavewaterowingthroughitregardlessofwhatzoneiscalling(usingVastherequiredbuertankvolume
will yield more conservative results).
  Qb=Boileroutput(BTU/hr).Formodulatingboilersusethelowreoutput.
  Qs=Smallestsystemheatingload(BTU/hr)
  t=Minimumacceptableburnerontime(minutes).Tenminutesistheminimumrecommendedvaluefort.
  ΔTD=Operatingcontrol’sdierential(i.e.thedierencebetweenthetemperatureatwhichtheoperatingcontrolturns
  otheburnerandthetemperatureatwhichtheburnerwillcomebackon).
 Example:Acondensingboilerhavinganoutputof150MBHwith5:1turndownistobeused.Thedierentialonthis 
 particularboilerisdenedintermsofa10F“dierentialabove”(temperatureaboveset-pointatwhichtheburnershuts
 o)anda5F“dierentialbelow”(temperaturebelowset-pointatwhichtheburnercomeson).Thesmallestheatingzoneon
 thesystemis5000BTU/hr.Wewanttheburnertorunforatleast10minutesanytimeitres.Thevolumeoftheboileris1
 gallon,theboilerlooppipingcontains5gallons,andthereis6gallonsinthesystempipingthatiscommontoallzones.
Solution: Min Output = 150MBH ÷ 5 = 30MBH = 30000 BTU/hr
Run Time = 10 minutes
 ΔTD=10F+5F=15F
The total volume of the water in the boiler, boiler loop, and common portion of the system loop is
 1+5+6=12Gal.
 Minimumrequiredbuertankvolumeistherefore
 33.3–12.0=21.3Gal.
B) TEMPERATURE CONTROL
Temperature Regulation-Forbestresults,regulatethesystemtemperatureusingasensororcontrollocatedinthebuertank
well. This well will accept a 3/8” sensor or capillary bulb equipped control. See Part VII for additional information.
ܸ ൌሺܾܳ െ ܳݏሻݔݐ
ͷͲͲݔοܶܦ 

ܸ ൌሺ͵ͲͲͲͲ െ ͷͲͲͲሻݔͳͲ
ͷͲͲݔͳͷ ൌ ͵͵Ǥ͵ܩ݈ܽǤ


WARNING
The boiler’s safety high limit(s) must remain in the location specied by the boiler manufacturer. Do
not move or replace these controls; if necessary, provide a separate operating control for regulation
of bu󰀨er tank temperature. Failure to observe this warning could result in property damage, personal
injury or loss of life.

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Predicting Temperature Supplied to the Heating System - The temperature of water supplied to the heating system is
 dependentupontheboilersupplytemperature,thesystemload,andtherelativeowratesthroughtheboilerandsystem
loops. The following rules of thumb can be used to estimate the system supply temperature:
  • BoilerLoopFlowGreaterThanorEqualtoSystemLoopFlow–Systemsupplytemperatureisequaltoboiler 
supply temperature
• Boiler Loop Flow Less Than System Loop Flow – The following equation predicts system temperatures:
Where:
Tss = System Supply Temp
    ΔTb=Boilertemperaturerise
    Vb=Boilerloopowrate
    Vs=systemowrate
    Tr=BoilerReturnandSystemReturnTemps(theoreticallyequaltoeachother)
Notethattheseequationsassumesteadystateconditionsandminimalturbulenceinsidethetank. Such turbulence is
 unavoidable,butcanbeminimizedasfollows:
  • Avoidunnecessarilyhighboilerorsystemowrates.
  • Iflooppipingissmallerthanthetankconnections,avoidmakingthereductionsatornearbuertankconnections.
  • Neverusetheairventordrainconnectionstocirculatewaterthroughthetank.
ܶݏݏ ൌ ߂ܾܶݔܸܾ
ܸݏ ൅ ܶݎ


WARNING
When the boiler res, the boiler’s supply temperature will immediately jump based on the boiler loop
ow rate and the boiler’s output. This can lead to burner cycling even with a correctly sized bu󰀨er
tank. To avoid this:
• D o n o t u s e t h e b o i l e r s u p p l y a s t h e o p e r a t i n g t e m p e r a t u r e r e g u l a t i o n p o i n t ; u s e t h e b u 󰀨 e r
tank’s well as described above.
• The sum of the maximum operating system set point, plus the rise across the boiler, should be
less than the boiler’s high limit setting.
V. LOCATING THE BUFFER TANK
 1)Table2.2showstheweightofeachbuertanklledwithwater.Makesurethatthelocationchosenforthebuertankis 
capable of supporting it.
 2)Locatethebuertankinalocationwherealeakinthetankortheadjacentpipingwillnotdamagethesurrounding
 structure.Ifthesurroundingareaishighlysusceptibletowaterdamage,installthetankinapanwithadrain.
WARNING
Failure to properly support the bu󰀨er tank could result in property damage, personal injury or death.

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VI. PIPING
 Thismanualshowsthreealternative“fourpipe”buertanksystems.Regardlessofthemethodused,observethefollowing
general requirements:
  • Followinganyspecialrequirementsthattheboilermanufacturerhasformaximumboilerlooplength,pipesize,or
boiler pump selection.
  • Figures6.1to6.3donotnecessarilyshowallfeaturesthatmayberequiredbytheboilermanufacturerand/or
applicable codes.
  • Notethattheuseofabuertankmayrequirealargersizeexpansiontankthanwouldotherwisebeneeded.
  • Atleastoneautomaticairventisrequiredinthesystem.Insomecases,suchasthepipingsystemshowninFigure6.1
   thisistheonlyautomaticairventthatisrequired(althoughadditionalmanualventsmaybeneededtoadequately
   purgethesystemduringinitialll).Incaseswherewaterisnotalwayscirculatingthoughthebuertank,asecond
automatic air vent and air separator is recommended in the common boiler loop piping.
Method #1: No indirect water heater used-Figure6.1showsrecommendedpipingwhenthereisnoindirectwaterheaterinthe
system.
Method#2–IndirectWaterHeater,BoilerHasExternallyMountedPump–Figure6.2showsonewayofusingabuertank
 andindirectwaterheaterinasystem.Recommendedpipingisdesignedtoavoidcirculatingwaterthroughthebuertank
 duringacallfordomestichotwater(DHW),asdoingsowillreduceDHWresponseandmayalsocauseoverheatingofthe
 watergoingtotheheatingsystem.Inthissystem,theboilerpumprunsduringacallforcentralheat(CH)andtheDHWpump
runs during a call for domestic hot water. Note that the DHW pump must be able to overcome both the pressure drop through
 theboilerandthatthroughtheindirectwaterheater,whileproducingtheowraterequiredbyboth.Whentheboilerhasa
 largepressuredrop,asisthecaseofmanywatertubeboilers,thismaybeimpracticalorveryexpensive.Insuchcases,use
Method #3 instead.
Method#3–IndirectWaterHeater,BoilerHasInternalPumpand/orHighPressureDrop–Figure6.3showsrecommended
 pipinginthiscase.AswithMethod#2,thissystemavoidscirculationthroughthebuertankduringacallforDHW.The 
 boilerpumprunsforeitheracallforCHorDHW.Twosystempumpsarerequired,oneforeachsideofthebuertank. 
 Thesecondsystempumponlyneedstoovercomethepressuredropthroughtheloopbetweenthebuertankandtheclosely
spaced Tees in the boiler loop.
FIGURE 6.1: PIPING METHOD #1 - HEATING ONLY, NO INDIRECT WATER HEATER

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FIGURE 6.2: PIPING METHOD #2 - INDIRECT WATER HEATER, LOW PRESSURE
DROP BOILER WITH EXTERNAL PUMP

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FIGURE 6.3: PIPING METHOD #3 - INDIRECT WATER HEATER, HIGH PRESSURE
DROP BOILER OR BUILT IN BOILER PUMP

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VII. WIRING and CONTROL SET-UP
Theexactmethodofwiringandsettingupthesystemcontainingthisbuertankdependsentirelyonfactorsdeterminedbythe
installerorsystemdesigner.Thefollowing,however,aresomegeneralguidelinesrelevanttothebuertank:
 1) Aspreviouslynoted,thecontrolwellinthebuertankisusuallythebestplacetoregulateheatingsystemtemperature.
This well will accept a 3/8” sensor or capillary bulb equipped control.
 2) ForVelocityPhantom,PhantomX,andRaptorcondensingboilers,thefollowingsensormaybeused:
   P/N103104-01(Honeywell32003971-003)
Wire this to the header sensor terminals on the boiler and follow the instructions in the boiler manual to use this sensor
  forCHtemperatureregulation.
 3) Ifasensorisused,itmusthavea3/8”nominaldiametersothatittssnuglyintothewell.Clampthesensorinplace 
  sothatitisnotaccidentlypulledout.Forbestresults,applyaheatconductivegreasetothesensor,suchasHoneywell
107408. The wiring between the header sensor and the control should be routed away from sources of electrical noise.
  Whereitisimpossibletoavoidsuchnoisesources,followshieldinginstructionsprovidedbytheboilerorcontrol
manufacturer.
• All wiring and grounding must be done in accordance with the authority having jurisdiction or,
in the absence of such requirements, with the National Electrical Code /NFPA 70). In Canada,
all wiring and grounding must be done in accordance with the Canadian Electrical Code,
Part 1 (CSA C22.1 - latest edition).
• Failure to properly wire electrical connections to the boiler may result in serious physical
harm.
• Electrical power may be suppled from more than one circuit. Make sure all power is o󰀨 before
attempting any electrical work.
• Never jump out or make inoperative any safety or operating controls.