Raypak 40 - 139 Gallon User manual

Raypak
Brand
Raypak
Model
40 - 139 Gallon
Type
User manual
Model size
40 H/V • 60 H/V • 80 V • 115 V • 139 V Gallon
Buffer / Decoupler
Systems and Tanks
Applications • Sizing • System Design
2
Buffer / Decoupler
Systems
In recent years there have been many ener-
gy-saving improvements to controls and
hydraulics associated with Hydronic Piping
Systems. Some of these may result in
reduced performance for high recovery boil-
ers if they reduce system flow or volume
enough to cause continuous or intermittent
short cycling based on small system vol-
ume. There is an easy remedy! Raypak has
developed an array of properly-sized Buffer
/ Decoupler systems and tanks. For
Hydronic systems, a primary/secondary
design is widely accepted to afford opti-
mum energy savings in multiple boiler
installations. The energy savings is even
more dramatic when adapted to direct
DHW systems. In each case, a decoupler is
employed. If system flow calculations indi-
cate the need for a small Buffer /
Decoupler, now it can be properly and eco-
nomically sized, combined with the decou-
pler function and is included during the
design phase. This small Buffer / Decoupler
approach retains the virtually-zero standby
loss during off periods that is unique to
high-recovery boilers.
Rapid system temperature fluctuations can
result from several design conditions. Some
stem from recently advanced technology,
some from less desirable and often outdat-
ed design approaches. Examples are: Light
Loads, Low System Flow Rates, and Rapid
Load Changes caused by large zones in
small systems. Sometimes the culprits are
the antiquated outdoor-reset three-way
valve designs, or systems incorporating the
energy-wasting central hydronic boiler fired
in summer for DHW-only using heat
exchangers.
Raypak’s recognized seasonal efficiency
optimization using primary / secondary
system designs often avoids all need for a
Buffer / Decoupler. Refer to the Raypak
website, www.Raypak.com for a whitepa-
per by Larry Ashton, PE. When more volume
is needed, properly-sized Buffer / Decoupler
tanks are the answer.
When you add the water content of a
Buffer / Decoupler tank, some may say that
you have the equivalent of a low-recovery
boiler. NOT SO! A separate minimally-sized
and well-insulated Buffer / Decoupler tank
mitigates virtually all radiation loss and
keeps the warm water in the system, not in
the boiler or exposed to the flue. The extra
water is then available to handle rapid or
unusual demand changes for whatever the
reason. The high-recovery boiler still stages
or modulates, and turns off on light loads.
Combined with Raypak’s standard
EconoMaster
®
residual heat recovery con-
trol, this eliminates the hot chimney effect.
Low-recovery water-filled boilers stay heat-
ed even during light demand, so the hot
chimney is ever present.
A bonus benefit that accrues when using
vertical Buffer / Decoupler tanks is their
inherent ability to serve as the system air
separator. The port configuration of
Raypak’s vertical Buffer / Decoupler was
laid out to match the flow pattern of an air
separator. By properly selecting the vol-
umes associated with each boiler system,
we are able to achieve very efficient air
separation. Combining the functions into
one piece of equipment keeps the equip-
ment design clean and limits the number of
connections, while still providing proper
boiler operation.
This brochure describes several systems and
applications where buffering additional vol-
ume is frequently needed, with proper
sizing guidelines, and piping diagrams.
Drawings are also included. Raypak offers
tanks to add the water volume needed
without over-sizing. For most systems, with
single or multiple boilers, properly-sized
Buffer / Decoupler tanks will range between
40 and 139 gallons; custom-sized tanks are
also available. All Raypak Buffer /
Decoupler tanks are specially designed to
incorporate the necessary number and size
of connections to match typical system pip-
ing requirements, without increasing field
piping costs. They are also constructed in
accordance with ASME codes and are
National Board listed.
3
Buffer / Decoupler
Sizing
Buffer / Decoupler - When
Needed?
• Any time reduced system volume can cause short-cycling.
• Multi-zone system can reduce flow and available volume to the
boiler.
• Main circulator with a VFD often reduces system flow below
boiler flow rate.
• Three-way valves utilized to achieve outdoor reset.
• VFD’s and/or 2-way zone valves can reduce system flow and
available water volume below boiler minimum.
Buffer / Decoupler sizing
The primary factors presented here that make a Buffer / Decoupler
tank appropriate is system flow that is lower than the on-line boiler
flow or low system volume with light loads that would otherwise
result in short-cycling of the boiler (When using multiple boilers use
the boiler minimum firing rate and boiler flow with only one boiler
on). When these conditions exist the following equation may be
utilized to size the Buffer / Decoupler tank:
(Boiler firing rate ÷ 1000 ) x Efficiency % x Min firing rate % x 0.15
= Buffer / Decoupler tank in gallons.
To use this equation first determine the following:
• The rated firing rate of selected boiler
• The certified boiler efficiency at full input rate
• The minimum boiler firing rate percentage
Examples:
• Model 753A MVB
Boiler rated input = 750,000 Btuh
Boiler Efficiency = 87%
Minimum firing rate = 14% of rated input
(750,000 ÷ 1000) x 87% x 14% x 0.15 = 14 gallons
Select 40 gallon standard tank
• Model 1505A XTherm
Boiler rated input = 1,500,000 Btuh
Boiler Efficiency = 96%
Minimum firing rate = 14% of rated input
(1,500,000 ÷ 1000) x 96% x 14% x 0.15 = 30 gallons
Select 40 gallon standard tank
• Note 1: When the minimum system flow is greater than the
boiler flow and the minimum active system volume is greater
than that calculated by the above equation the Buffer tank is
not needed.
• Note 2: All Buffer / Decoupler tanks shown perform the intend-
ed decoupling function.
• Note 3: All Raypak vertical Buffer / Decoupler tanks contain a
1 NPT fitting at the top. If the tank is mounted at the system
high point, it can also serve as the mounting location for the air
vent. This eliminates the need for an additional field connection.
• Note 4: For information regarding typical minimum and maxi-
mum variable primary pump flows in multiple boiler systems,
see www.raypak.com tech corner, Larry Ashton’s white paper
on optimizing efficiency with multiboiler system.
4
1 NPT
G
AUGE
1/2 NPT
TO BOILER
(4X) 2-1/2 NPT
1 NPT
DRAIN
2 NPT w/PLUG
INSPECTION OPENING
1
2
1
1
“
±
3
8
“ TYP.
“
“
4
5
8
2
“ TYP.
10
“
4
5
0
3
4
3
16”
(2X) BAFFLE
17
1
4
“
w/STANDOFF
ASME NAMEPLATE
F
ROM SYSTEM
(BAFFLED)
T
O SYSTEM
1/2 NPT
SENSOR WELL
FROM BOILER
(BAFFLED)
49
7
8
“±
3
8
“
5”
w/STANDOFF
A
SME NAMEPLATE
(
2X) BAFFLE
20”
3
“10
4
21
1
4
“
(2X) 1 NPT
D
RAIN
I
NSPECTION OPENING
1
/2 NPT
SENSOR WELL
(2X) 2 NPT w/PLUG
TO BOILER
(4X) 2-1/2 NPT
2
24”
1
2”
1
“
TYP.
3
4
FROM SYSTEM
(BAFFLED)
“
TYP.
F
ROM BOILER
(BAFFLED)
G
AUGE
T
O SYSTEM
Model 40 Gal.
Model 60 Gal.
150 Pounds
105 Pounds
Buffer / Decoupler
Horizontal Configuration
• Optional mounting kits are available for use with Hi Delta boilers.
5
Buffer / Decoupler
Vertical Configuration
20
(
4
X)
ON
1
8
-1
/
4
”
BC
3/4”
HO
L
E
SEN
SO
R
P
O
R
T
1
/
2
N
P
T
2
N
P
T
w
/
P
L
U
G
(
I
N
SP
EC
T
I
O
N
ASM
E N
A
M
EP
L
A
T
E
O
N
BR
A
C
KET
2
N
P
T
w
/
P
L
U
G
I
N
SP
EC
T
I
O
N
A
N
D
D
R
AI
N
1
2
”
4
-
5
/
1
6
”
8
-
5
/
8
”
1
N
P
T
5
-
1
/
1
6
”
3
/
4
”
T
YP
.
(
4
X
)
2
-
1
/
2
N
P
T
BOTTOM V
IE
W
T
O
P
V
I
EW
F
R
ONT EL
EVA
TI
ON
FI
NI
SH:
I
NTERI
O
R: UNPA
I
NTED
EX
TERI
O
R: P
RI
ME
A
SME SEC
TI
O
N
VI
I
I
,
‘U
’
ST
A
MP
ED
MAX. O
P
ERATI
NG
TEMP: 250 DEG
REES F
MAX.
W
O
RKI
NG
P
RESSURE: 150 P
SI
G
TO
LERA
NCE: ±
1/4
90
45
2
4
”
5
6
-
7
/
8
±
3
/
8
”
6
”
ST
AN
D
A
R
D
BA
F
F
L
ES
1
9
-
1
1
/
1
6
±
1
/
2
”
Model 60 Gal.
16
BOTTOM VIEW
(4X)
ON 14-1/2” BC
3/4” HOLE
SENSOR PORT
1/2 NPT
STANDARD
BAFFLES
ASME NAMEPLATE
ON BRACKET
3/4” TYP.
AIR VENT
1/2 NPT w/PLUG
2 NPT w/PLUG
INSPECTION
AND DRAIN
10-7/8”
4-1/8”
6
-5/8”
8
-1/4”
1 NPT
(
4X) 2-1/2 NPT
T
OP VIEW
FRONT ELEVATION
FINISH:
INTERIOR: UNPAINTED
EXTERIOR: PRIME
ASME SECTION VIII, ‘U’ STAMPED
MAX. OPERATING TEMP: 250 DEGREES F
MAX. WORKING PRESSURE: 150 PSIG
TOLERANCE: ± 1/4
90
45
21-3/4”
57-1/8±3/8”
21±3/8”
Model 40 Gal.
•
Custom Buffer / Decoupler tank sizes are available.
Please contact your sales rep for sizing and
pricing.
6
Buffer / Decoupler
Vertical Configuration
G
ENERAL
SPECI
FI
CATI
O
NS:
ST
AND
ARD BAFFL
E:
4
-1
/
2
X 7
”
,
3
0
4
S.
S.
FI
NI
SH
:
I
NTERI
O
R:
U
NPAI
NTED
EXTERI
O
R:
PRI
M
E
ASME SEC
TI
O
N V
I
I
I
,
‘
U’ ST
A
MPED
M
A
X.
O
PERAT
I
NG
TEMP
:
2
5
0
DEG
REES
F
MA
X.
WO
RKI
NG
PRESSU
RE:
1
5
0
PSI
G
WEI
G
H
T
:
3
2
5
T
O
L
ERAN
CE:
±
1
/
4
1
8
5
8
“
4
”
4
5
1
4
“
2
7
3
8
“
(
A
I
R
V
E
N
T)
1
N
PT
1
N
PT
A
N
GL
E
L
E
GS
4
”
1
5
0#
A
N
S
I
R
F
SO
(
GA
U
G
E
)
(
3
X)
2
-
1
/
2
X
2
-
1
/
2
(
w/
BA
FFL
E
)
1
/
2
N
PT
(
w/
B
A
F
F
L
E
)
(
’
T’
S
TA
T)
w/
STA
N
D
OFF
1-
1
/
2
N
P
T
A
SM
E
N
A
M
E
PL
A
TE
(
D
R
A
I
N
)
1
N
PT
(
PL
U
GG
E
D
)
(
2
X
)
2
N
PT
4
”
1
5
0#
A
NSI
RFSO
4
”
1
5
0#
A
NSI
RFSO
1
0
1
1
2
”
“
5
8
1
6
8
2
1
3
2
“ “±
”
6
”
8
2
1
3
8
“
T
Y
P.
5
”
TY
P.
F
R
ON
T
E
L
E
V
A
T
I
O
N
T
O
P
V
I
E
W
9
0
18
0
0
(
2
X
)
L
I
F
T
L
U
GS
27
0
2
4
”
ON
2
2
-1
/2
B.C.
3
/
4
”
HOL
E(3X
)
4
”
1
5
0
#
A
N
SI
R
F
SO
B
OTTO
M VI
EW
Model 139 Gal.
D
90
0
(2X) LIFT LUGS
270
A
5”
(2X) STD BAFFLE
BOTTOM VIEW
ON 18-7/16 B.C.
(3X) 3/4” HOLE
4” 150# ANSI RFSO
(3X) 2-1/2 X 2-1/2
(
2X) 2 NPT
(
GAUGE)
(
PLUGGED)
1 NPT
1
-1/2 NPT
(
w/BAFFLE)
(T&P) PORT
4
” 150# ANSI RFSO
4” 150# ANSI RFSO
w
/STANDOFF
ASME NAMEPLATE
(’T’ STAT)
1
/2 NPT
(AIR VENT)
1
NPT
(DRAIN)
1 NPT
ANGLE LEGS
4
” 150# ANSI RFSO
(
w/BAFFLE)
4
”
C
3
“
1
6
T
YP.
5”
B
16
69”
3
8
“
TYP.
TOP VIEW
FRONT ELEVATION
180
4
GENERAL SPECIFICATIONS:
STANDARD BAFFLE: 4-1/2 X 7”, 304 S.S.
FINISH:
INTERIOR: UNPAINTED
EXTERIOR: PRIME
ASME SECTION VIII, ‘U’ STAMPED
MAX. OPERATING TEMP: 250 DEGREES F
MAX. WORKING PRESSURE: 150 PSIG
TOLERANCE: ± 1/4
80 20 10 10-1/2 43 200
115 24 11 9-1/8 41-1/4 240
Tank Dimensions & Weight
A
C D
B
Weight
Model 80 & 115 Gal.
Gal.
• Custom Buffer / Decoupler tank sizes are available.
Please contact your sales rep for sizing and
pricing.
7
Buffer / Decoupler
Applications
FILL
WATER
E
XPANSION
TANK
WATER
PRESSURE
R
EGULATOR
B
UFFER
TANK
S
YSTEM
WATER
S
ENSOR
THERMOMETER
AIR VENT
ZONE 3
ZONE 2
ZONE 1
SYSTEM PUMP
SYSTEM
SUPPLY
ISOLATION
VAVLE (TYP)
SYSTEM
RETURN
BOILER-MOUNTED
PRESSURE
RELIEF VALVE
PUMP LOCATION
ON MODELS
WITHOUT
INTEGRAL PUMP
OPTIONAL INTEGRAL PUMP
(CERTAIN MODELS)
BUFFER
TANK
FILL
WATER
EXPANSION
TANK
SYSTEM
WATER
SENSOR
WATER
PRESSURE
REGULATOR
THERMOMETER
AIR VENT
ISOLATION
VALVE (TYP)
SYSTEM
RETURN
SYSTEM
SUPPLY
SYSTEM PUMP
ZONE 1
ZONE 2
BOILER-MOUNTED
PRESSURE
RELIEF VALVE
OPTIONAL INTEGRAL PUMP
(CERTAIN MODELS)
PUMP LOCATION
ON MODELS
WITHOUT
INTEGRAL PUMP
Light Loads
L
ight
lo
ads in
clude
a load t
h
at
is le
ss t
han t
he
min
im
um fir
in
g r
at
e
o
f t
h
e
bo
ile
r
a
nd lo
w
v
o
lume
in
t
h
e
h
e
a
t
in
g lo
o
p
.
T
h
is can
r
e
sult
in
sh
or
t
cy
clin
g of t
he
bo
ile
r.
A
ddin
g a Bu
ffe
r
/ D
e
co
u
ple
r
t
an
k
t
h
at
is he
at
e
d by
t
h
e
bo
ile
r
w
ill pr
ov
ide
a
“fly
w
h
e
e
l e
ffe
ct
” w
he
r
e
t
he
Buffe
r
/ D
e
co
uple
r
t
an
k
can
car
r
y
t
h
e
h
e
at
ing loa
d for
a fe
w
minu
t
e
s w
it
h t
h
e
bo
ile
r
in
t
he
o
ff m
o
de
.
A
lso
, w
he
n
t
he
bo
ile
r
fir
e
s it
w
ill
st
ay
on lon
g e
n
o
ugh
t
o
r
e
he
at
t
h
e
Buffe
r
/ D
e
co
u
ple
r
t
an
k
in
cr
e
asin
g t
h
e
du
r
at
io
n of t
h
e
o
ff an
d on
cy
cle
s.
Rapid Load Changes
Rapid load changes can result from turning off or on a major zone within the heating system. These rapid changes can be geatly
reduced with a properly-applied buffer / decoupler tank.
FILL
WATER
THERMOMETER
SYSTEM
WATER
SENSOR
BUFFER
TANK
AIR VENT
EXPANSION
TANK
S
YSTEM
RETURN
WATER
P
RESSURE
REGULATOR
3-WAY
O
UTDOOR
RESET VALVE
SYSTEM PUMP
SYSTEM
SUPPLY
ISOLATION
VALVES (TYP)
BOILER-MOUNTED
PRESSURE
RELIEF VALVE
PUMP LOCATION
ON MODELS
WITHOUT
INTEGRAL PUMP
OPTIONAL INTEGRAL PUMP
(CERTAIN MODELS)
8
Buffer / Decoupler
Applications
Three-way Valves
Three-way valves have been utilized in the past to accomplish outdoor reset with high-mass boilers that traditionally require continuous
high-temperature operation to prevent condensation and/or thermal shock. In such systems the boiler is maintained at or above the highest
temperature required and then blended down via the three-way valve to achieve the desired heating loop temperature. Raypak offers several
outdoor reset packages that accomplish outdoor reset by directly resetting the boiler operating temperature. However, for some existing sys-
tems, or when there is a firm system specification for a three-way valve, the Buffer / Decoupler tank can be plumbed into the boiler
loop to create some “flywheel effect”.
Variable System Flow
Variable system flow rates occur when variable-speed pumps are applied to the system. Variable system flow also occurs when two-way
valves are utilized to control flow to heating zones. During lower system flow operation, the boiler flow rate exceeds the system flow rate,
boiler outlet water will short circuit back to the boiler causing a rapid rise in boiler temperature and possibly trip the high-limit. Buffer /
Decoupler tanks can stabilize the temperature in these cases.
9
Buffer / Decoupler
Applications
BUFFER
TANK
SYSTEM
WATER
SENSOR
THERMOMETER
AIR VENT
ISOLATION
VALVE (TYP)
SYSTEM
PROCESS
PROCESS PUMP
PLATE AND FRAME
HEAT EXCHANGER
SYSTEM PUMP
WATER
PRESSURE
REGULATOR
EXPANSION
TANK
FILL
WATER
BOILER-MOUNTED
PRESSURE
RELIEF VALVE
OPTIONAL INTEGRAL PUMP
(CERTAIN MODELS)
PUMP LOCATION
ON MODELS
WITHOUT
INTEGRAL PUMP
Process Fluid Heating
In some processes or other similar applications, it is necessary to isolate the boiler circulating loop from the fluid being heated. (E.g. plating
tanks and aquariums.) In these cases the boiler primary loop often has a low water volume and may require a Buffer / Decoupler tanks.
Raypak, Inc. • 2151 Eastman Avenue, Oxnard, CA 93030 • phone: (805) 278-5300 • fax: (800) 872-8725 • www.raypak.com
© 2011 Raypak, Inc. Cat. No. 2000.82-G Effective: 11-01-16 Replaces: 03-01-15
Buffer / Decoupler
Applications
THERMOMETER
HOT WATER
SUPPLY
SYSTEM
WATER
SENSOR
PUMP LOCATION
ON MODELS
WITHOUT
INTEGRAL PUMP
OPTIONAL INTEGRAL PUMP
(CERTAIN MODELS)
BOILER-MOUNTED
PRESSURE
RELIEF VALVE
Indirect For DHW
It is NEVER good to design systems which fire hydronic heating boiler(s) during the warmer weather when space heat is not needed, just to
meet domestic water needs. Many existing “summer boiler” installations use an energy-wasting heat exchanger for DHW when no space
heating is needed. Separating the domestic water from the space heating source can save far more energy than even a boiler upgrade to a
higher efficiency unit. Both upgrades simultaneously are the real solution. Owners repeatedly experience seasonal operating savings well in
excess of 50% when this is done, which makes payback very short.
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Raypak 40 - 139 Gallon User manual

Raypak
Brand
Raypak
Model
40 - 139 Gallon
Type
User manual
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