Crown’s 3 Recommendations; Impact of System Piping; RTC Return Temperature Control- Page 5

Burner Mounting Plates and Adapter Plates

FRONT VIEW

SIDE VIEWS

4” STANDARD

IDENTIFICATION NUMBER

‘A’ DIA

HOLE

‘B’ DIA

BOLT CIRCLE

‘C’

(REF)

4

8

8” EXTENDED

CAST IRON BURNER MOUNTING PLATES

STANDARD BURNER

ADAPTER PLATE

I.D.

‘A’ 

‘B’ 

‘C’

BOILER MODEL 

PART NO. 

NO. 

DIA. 

DIA. 

REF.

24-03 THRU 24-05 

330400 

920 

4-3/4 

10 

7-1/16

24-06 THRU 24-08 

330401 

921 

6-1/8 

10 

7-1/16

24-09 THRU 24-12 

330402 

922 

6-3/4 

10 

7-1/16

BECKETT (“CF” SERIES) BURNER ADAPTER PLATE

I.D.

‘A’ 

‘B’ 

‘C’

BOILER MODEL 

PART NO. 

NO. 

DIA. 

DIA. 

REF.

24-03 THRU 24-06 

330400 

920 

4-3/4 

10 

7-1/16

  24-07    THRU 24-08 

330401 

921 

6-1/8 

10 

7-1/16

24-09 THRU 24-11 

330403 

923 

7-1/4 

10 

7-1/16

24-12 

330404 

924 

8-1/8 

10 

7-1/16

BECKETT (“CG” SERIES) BURNER ADAPTER PLATE

Note:

1.  A burner adapter plate is needed for each boiler.

Control Tappings

  TAPPING 

SIZE

   LOCATION 

(IN.) 

STEAM BOILER

WATER BOILER

A 

4 

Supply 

Supply

B 

4

Plug (24-03 thru 24-06) 

Plug

Supply (24-07 thru 24-12)

C 

3 

Blow-Off Valve 

Return

D 

3 

Return

Plug (24-03 thru 24-11)                 

Return (24-12)

E 

3 

Plug 

Blow-Off / Drain Valve

F 

3 

Plug 

Plug

G 

1-1/2 

Safety Valve / Surface Skim Tap 

Relief Valve

J1 

1 

Plug 

Plug

J2 

1 

Float L.W.C.O. 

Plug

K 

3/4 

Plug 

Probe L.W.C.O.

M 

3/4 

Operating Pressure Limit Control  

Operating Temperature Limit Control                                                  

N 

3/4

Hi Pressure 

Hi Temperature  

Limit Control / Manual Reset 

Limit Control/Manual Reset

P 

1/2 

Gauge Glass/#67 L.W.C.O. 

Plug

Q 

1/2 

Steam Gauge (Bush to 1/4”)

Temperature/Pressure                                                

Gauge (Bush to 1/4”)

S 

3/4 

Tankless Heater Control 

Tankless Heater Control

T 

3/4 

Firing Rate Pressure Control 

Firing Rate Temperature Control

Series 24 Minimum Piping 

Recommendations – Water Boiler

Impact of System Piping

 –

 Many hot water systems  

are zoned. Some also use mixing valves to control the water 
temperature in the system. These features can cause the 
flow through the boiler to vary dramatically, depending on 
the status of the zones or mixing valves. In addition, the 
large water content of many commercial systems has the 
potential to subject the boiler to operation with low return 
temperatures for an extended period of time. These factors 
can shorten the life of a boiler due to thermal shock or flue 
gas condensation.     

Crown’s 3 Recommendations

 – 

On the following 

pages, CROWN provides three basic recommendations  
for near-boiler piping that are intended to maximize the  
life expectancy of the boiler by protecting it from flue gas 
condensation and thermal shock. Each protects the boiler  
by making sure that both of the following conditions are met:

■

   The flow 

through the boiler

 is high enough to 

ensure a temperature rise of less than 40°F 

■

  The return temperature does not fall below 135°F 

for an extended period of time. 

RTC Return Temperature Control

 –

 Piping 

Recommendation 3 makes use of CROWN’s optional  
RTC (Return Temperature Control). This control provides an 
economical and effective way of protecting the boiler from 
thermal shock and condensation. It can be incorporated into 
most hot water systems with minimal modifications to the 
system design and operation. When this option is used on 
multiple Series 24s, one RTC is required for each boiler.   
The CROWN RTC is also available with an outdoor reset 
option. This provides additional energy savings by 
modulating system water temperature to match the  
building load requirements.  

Commercial Hot Water or Steam Boiler

Commercial Hot Water or Steam Boiler

FRONT VIEW

BACK VIEW

F

E

J2

J2

J1

J1

Q

K

M

G

T

B

P

P

N

S

A

D

C