Recommendation 1 — Use when:
•system return water is not less than 135° F for prolonged periods of time
•system flow does not impact flow through the boiler
Pipe Sizing and Notes
| SUPPLY |
| RETURN PIPING SIZE (IN) |
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| PIPING |
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| RETURN | RETURN |
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| SIZE (IN) |
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| HEADER | BRANCH |
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| (1) | RETURN (2) | (2A) | (QTY.) SIZE (2B) |
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| 20°F |
| 40°F | 20°F | 40°F | 20°F | 20°F |
|
MODEL | DROP | DROP | DROP | DROP | DROP | DROP |
| |
2 |
| 2 | — | — | NOTES: | |||
2 |
| 2 | — | — | ||||
2 |
| 2 | — | — | 1.All piping is schedule 40. | |||
| — | — | 2.Pipe sizes listed are based on a 20°F or 40°F differential (temperature drop). | |||||
| 2 | 2 | — | — | Select one to match application. | |||
| 2 | 2 | — | — | 3.When specified return piping size is less than 3”, install 3” X 12” nipple and appropriate | |||
3 |
| 2 | 3 | 2 | — | — | size bell reducer directly into boiler return tapping as shown. | |
3 |
| 3 | — | — | 4.Drain valve — ball valve preferable, gate valve acceptable alternative | |||
3 |
| 3 | — | — | (supplied by others). | |||
4 |
| 4 | 3 | (2) 3 | - Minimum valve size per ASME code is 3/4” NPT. | |||
Figure 31: Series 24 Minimum Piping Recommendation 1 - Water Boiler
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