1-805-484-2992
Quotes - Engineering - Sales
HTWU Series
| PRODUCT | TYPE | STYLE | RATING |
|---|---|---|---|
| Heat Exchanger | Shell & Tube | High Tube Pressure | 150 PSI shell / 400 PSI tube |
Specifications
Configuration & Size
Shell Diameter:
4" to 12"
Shell Length:
48" to 120"
Tubes:
3/4" O.D. Copper
Passes:
2, 4 and 6 Pass
Brand:
Bell & Gossett
Materials
- Bonnets: Cast Iron
- Shell: Steel
- Tubes: Copper
- Tubesheet: Steel
HTWU Series High Tube Pressure Heat Exchangers
When the Tube Side Runs Above the Standard Rating
Most Bell & Gossett shell and tube units carry a 125 or 150 PSI tube-side rating, which covers the great majority of hydronic and process duty. The HTWU exists for the cases it does not: the tube side is rated to 400 PSI while the shell stays at 150.
Tall buildings are the classic case. Static head alone puts a high-rise hydronic riser above 150 PSI at the bottom of the stack, and adding pump head on top of that quickly exceeds a standard rating. The HTWU handles the pressure without moving the whole selection into engineered construction.
High head pumping circuits are the other. Long distribution runs, deep well systems and circuits with significant elevation change all raise tube-side pressure beyond what the standard range permits, even where the temperatures involved are unremarkable.
The asymmetry is deliberate. Raising the tube-side rating is far cheaper than raising the shell rating, because tubes and tubesheets are small pressure boundaries and a shell is a large one. Putting the high-pressure fluid in the tubes and keeping the shell at 150 PSI is what makes the HTWU an economical answer rather than a costly one.
Everything else follows the WU. Removable U-tube bundle, cast iron bonnets, steel shell and tubesheet, and 2, 4 and 6 pass tube-side arrangements across a 4 to 12 inch shell range.
A 400 PSI tube-side rating for high-rise risers and high head circuits, at standard lead times.
Request a QuoteHTWU Series Applications
Calculate the Pressure Where the Unit Sits
The pressure that matters is the pressure at the exchanger, not at the top of the system. In a tall building that means static head measured from the highest point in the circuit down to the plant room, plus pump head, plus whatever the expansion vessel is pressurised to. It is entirely common for a riser to sit comfortably inside a standard rating at the top of the stack and outside it in the basement, which is exactly where the exchanger usually lives.
The HTWU answers that case by rating the tube side to 400 PSI while leaving the shell at 150. The asymmetry is deliberate and it is what keeps the construction affordable: a shell is a large-diameter pressure boundary and uprating it costs disproportionately more, whereas tubes and tubesheets are small ones. Put the high-pressure fluid in the tubes and the duty is met at a fraction of the cost of uprating both sides.
Check temperature separately, because the two limits are set independently. The HTWU is rated to 375°F, higher than the WU's 300°F but the same as the SU. A duty can sit inside one limit and outside the other. Call and talk it through with an engineer: 1-805-484-2992
