Taco U-tube liquid-to-liquid shell and tube heat exchanger

Heat Exchangers

Taco heat exchangers for HVAC, domestic hot water and process duties. U-tube shell and tube units cover liquid-to-liquid and steam-to-liquid service in 4 to 30 in shells, up to 1,378 sq ft of heating surface. Leak Guard double wall units put two walls between boiler water or steam and potable water. TB Series brazed plate exchangers handle up to 696 GPM in a compact, gasket-free unit. Tank heating units bolt into an existing storage tank. Shell and tube models are ASME Section VIII Division 1, 150 psig standard on both sides and certified to NSF/ANSI 372. All products are genuine, factory-new equipment in original manufacturer packaging, sold and supported by Watermain Supply, an independent industrial supplier. Send both sides of the duty for a Taco selection: sales@watermainsupply.com or 1-888.510.4036.

6 products
Sort by:
Best selling
Sort by:
Best selling
Taco U-Tube Steam-to-Liquid Heat Exchanger - Shell and Tube, ASME, 2 or 4 Pass
Taco U-tube steam-to-liquid shell and tube heat exchanger

Taco

Free Shipping $499 or more

Taco U-Tube Steam-to-Liquid Heat Exchanger - Shell and Tube, ASME, 2 or 4 Pass

From $5,252.34
Taco U-Tube Liquid-to-Liquid Heat Exchanger - Shell and Tube, ASME, 2 or 4 Pass
Taco U-tube liquid-to-liquid shell and tube heat exchanger

Taco

Free Shipping $499 or more

Taco U-Tube Liquid-to-Liquid Heat Exchanger - Shell and Tube, ASME, 2 or 4 Pass

From $6,620.87
Taco TB Series Brazed Plate Heat Exchanger
Taco TB Series brazed plate heat exchangers

Taco

Free Shipping $499 or more

Taco TB Series Brazed Plate Heat Exchanger

From $435.82
Taco Tank Heating Unit - U-Tube Bundle, 4 to 16 in
Taco tank heating unit, U-tube bundle with cast head

Taco

Free Shipping $499 or more

Taco Tank Heating Unit - U-Tube Bundle, 4 to 16 in

From $4,213.77
Taco Leak Guard Double Wall Steam-to-Liquid Heat Exchanger - Shell and Tube, ASME
Taco Leak Guard double wall steam-to-liquid heat exchanger

Taco

Free Shipping $499 or more

Taco Leak Guard Double Wall Steam-to-Liquid Heat Exchanger - Shell and Tube, ASME

From $15,829.66
Taco Leak Guard Double Wall Liquid-to-Liquid Heat Exchanger - Shell and Tube, ASME
Taco Leak Guard double wall liquid-to-liquid heat exchanger

Taco

Free Shipping $499 or more

Taco Leak Guard Double Wall Liquid-to-Liquid Heat Exchanger - Shell and Tube, ASME

From $19,892.74

Heat Exchangers

HVAC, Hot Water & Process · Taco

Heat Exchangers
Shell and Tube, Double Wall and Brazed Plate

ASME U-tube shell and tube heat exchangers for liquid-to-liquid and steam-to-liquid service, Leak Guard double wall units for potable water, compact TB brazed plate exchangers and tank heating units. 4 to 30 in shells up to 1,378 sq ft of heating surface, brazed plate units to 696 GPM, selected by computer for your duty.

Taco U-tube liquid-to-liquid shell and tube heat exchanger
4 to 30 inShell diameters
1,378 sq ftMax heating surface
696 GPMMax flow, brazed plate
150 psigStandard, ASME VIII Div. 1
NSF/ANSI 372Shell and tube units

A heat exchanger moves heat between two fluids that must never mix. It heats domestic water from boiler water or steam, isolates a chilled water plant from a process or tower loop, transfers heat between a boiler and a snow melt or radiant system, and heats storage tanks. The right type depends on the fluids, the temperatures and pressures, whether potable water is involved, and how much space the mechanical room has.

Watermain Supply supplies the Taco heat exchanger line online with engineering-led selection: U-tube shell and tube units for liquid-to-liquid and steam-to-liquid service, Leak Guard double wall units, TB Series brazed plate exchangers and tank heating units. Every Taco shell and tube unit is selected by computer for the duty; send us both sides of the duty and we return the selection: sales@watermainsupply.com or 1-888.510.4036. All products are genuine, factory-new equipment in original manufacturer packaging, sold and supported by Watermain Supply, an independent industrial supplier.

Heat Exchanger Selection GuideMatch the type to the fluids and the job Sizing the LoadBTU/hr, GPM and steam worked example HVAC Pump & Circulator CalculatorSize the pumps on each side

Will a Taco Heat Exchanger Work for Your System?

The four questions engineers and contractors ask first, answered from Taco’s published data.

Warranty

TB brazed plate units are covered for 1 year from start-up or 18 months from shipment, whichever comes first, under Taco’s limited warranty. For the shell and tube and tank heating lines we confirm the current Taco terms with your quote.

Built to Last

Shell and tube units are designed, constructed and tested to ASME Section VIII Division 1, fabricated in-house by Taco, with National Board and CRN registration available. U-tube bundles expand freely with temperature, so thermal cycling does not stress the tube joints.

The Fit Limits

Shell and tube: 150 psig both sides and 375°F standard, higher by option. Brazed plate: up to 812 psi by pressure class, fluids compatible with stainless steel and copper or nickel. Tank heating units: 150 psig, 375°F.

Size It Now

Send both sides’ flows, entering and leaving temperatures and allowable pressure drops, and we return the Taco selection.

Email the Duty

Or call 1-888.510.4036

Taco Heat Exchanger Families

Shell and tube for steam, high temperature and large duties; double wall where potable water needs two walls; brazed plate where space is tight.

Taco U-tube liquid-to-liquid heat exchanger

U-Tube Shell and Tube

Liquid-to-liquid and steam-to-liquid

4-30 inShells
1,378 sq ftMax surface
2 or 4Pass
150 psigBoth sides std

ASME Section VIII Division 1 shell and tube units with a U-tube bundle that expands freely with temperature. Copper tubes and steel shell standard, with a wide choice of shell, head, tube and tube sheet materials so Taco can match the unit to the application.

  • Liquid-to-liquid: 192 builds online, 4.6 to 1,378 sq ft
  • Steam-to-liquid: 204 builds online, steam and condensate connections per model
  • Tubes to 400 psig and shell to 250 psig optional
  • NSF/ANSI 372 certified and listed
Best forDomestic water heating from boiler water or steam, process heating, and large heating plant duties.
View Liquid-to-Liquid
Taco Leak Guard double wall liquid-to-liquid heat exchanger

Leak Guard Double Wall

Two walls between the fluids

4-20 inShells
1,211.8 sq ftMax surface
Double wallCopper tubes
NSF/ANSI 372Certified

Double wall U-tube shell and tube heat exchangers for installations such as potable water heating where codes call for double wall separation. The steam-to-liquid version uses double wall copper tubes with an enhanced heating surface.

  • Liquid-to-liquid: 135 builds online, 9.1 to 1,087.5 sq ft
  • Steam-to-liquid: 140 builds online, 9.1 to 1,211.8 sq ft
  • Double wall cupro-nickel tubes optional
  • ASME Section VIII Division 1, 2 or 4 pass
Best forDomestic hot water in hospitals, hotels, schools and multifamily buildings where code requires double wall separation.
View Leak Guard Liquid
Taco TB Series brazed plate heat exchangers

TB Series Brazed Plate

Compact, gasket-free

696 GPMMax flow
0.63-3.9 inPorts
812 psiMax by class
246Builds online

Stainless steel channel plates brazed with copper, or nickel on the N versions, into a compact unit for water, refrigerant, steam and oil duties. Pick the model, version and plate count from the Taco selection; the TB16 double wall adds improved leak detection.

  • Seven models, TB5 to TB120 and TB65
  • Copper or nickel brazed; double wall TB16
  • Pressure classes S, M, F and H per EN 13445
  • Externally threaded connections standard
Best forHydronic isolation, heat pumps, snow melt and radiant systems, small chiller and process duties where floor space is tight.
View TB Brazed Plate

More Taco Heat Exchangers

Taco U-tube steam-to-liquid heat exchanger

U-Tube Steam-to-Liquid

4-30 in shells · 1 to 1,378 sq ft · 2 or 4 passSteam heating of waterTaco Leak Guard double wall steam-to-liquid heat exchanger

Leak Guard Steam-to-Liquid

4-20 in shells · double wall enhanced tubesPotable water from steamTaco tank heating unit, U-tube bundle with cast head

Tank Heating Units

4-16 in · 12 to 120 in long · single or double wallBolts into a storage tankTaco shell and tube heat exchanger with four flanged connections

Leak Guard Liquid-to-Liquid

4-20 in shells · 9.1 to 1,087.5 sq ftDouble wall, NSF/ANSI 372

Gasketed PF Series plate and frame heat exchangers, ASME code stamped with 1 to 12 in ports and flows to 7,163 GPM, are engineered to order. Email the duty for a quote.

Taco Heat Exchanger Comparison

The families side by side, from the data on each product page. Highlighted cells are the figures that usually decide the choice.

Family Service Size range Heating surface or flow Pressure / temp Walls
U-Tube Liquid-to-Liquid Liquid to liquid 4-30 in shells 4.6-1,378 sq ft 150 psig both sides, 375°F std Single
U-Tube Steam-to-Liquid Steam to liquid 4-30 in shells 1-1,378 sq ft 150 psig std, 375°F std Single
Leak Guard Liquid-to-Liquid Liquid to liquid 4-20 in shells 9.1-1,087.5 sq ft 150 psig both sides, 375°F std Double
Leak Guard Steam-to-Liquid Steam to liquid 4-20 in shells 9.1-1,211.8 sq ft 150 psig std, 375°F std Double, enhanced
TB Brazed Plate Liquid, refrigerant, steam, oil 0.63-3.9 in ports to 696 GPM to 812 psi by class Single; double on TB16
Tank Heating Unit Boiler water or steam into a tank 4-16 in, 12-120 in long By diameter and length 150 psig, 375°F Single or double

From the Taco submittal data sheets, catalogs and price sheets on each product page. Tubes to 400 psig, shells to 250 psig and higher temperatures are optional on the shell and tube units.

Quick rule. Steam on one side: U-tube steam-to-liquid. Potable water and a code that calls for double wall: Leak Guard. Clean liquids and little space: TB brazed plate. Heating a storage tank you already have: tank heating unit. Very large liquid duty, such as a waterside economizer: PF plate and frame by quote.

Shell and Tube, Brazed Plate or Plate and Frame?

Taco is the heat exchanger line we carry today, so the honest comparison is between technologies. Each one wins somewhere.

Question U-tube shell and tube Leak Guard double wall Brazed plate (TB) Plate and frame (PF, by quote)
Steam service Yes, steam-to-liquid models Yes, steam-to-liquid models Some models, by duty Liquid duties
Footprint Largest Large Smallest Fraction of shell and tube
Gaskets between fluids None None None, brazed Glue-free gaskets, leak shows across the seal
Serviceable or expandable Bundle by model Bundle by model Replace the unit Plate by plate; frame takes 10% more plates
Potable separation Single wall Double wall Double wall on TB16 Single plate
Thermal cycling U-tubes expand freely U-tubes expand freely Compact, rigid pack Plates in a bolted frame

Verdict. Shell and tube is the safe choice for steam, high temperature, dirty fluids and large heating plants, and its U-tube bundle tolerates thermal cycling. Leak Guard is the answer wherever the code calls for double wall separation of potable water. Brazed plate wins on size for clean hydronic and heat pump loops. Plate and frame wins on very large liquid duties and on serviceability, since plates can be added or replaced one at a time.

Which Heat Exchanger Do You Need?

Typical selections by application. Every unit is selected by Taco for the exact duty; we confirm the selection before it ships.

Application Heating medium Recommended Notes
Domestic hot water, hospital or hotel Boiler water Leak Guard Liquid-to-Liquid Double wall where code requires it.
Domestic hot water from a campus steam plant Steam Leak Guard Steam-to-Liquid Size the condensate connection per model.
Heating hot water from steam Steam U-Tube Steam-to-Liquid Closed heating loop, single wall.
Process or heating loop isolation Boiler or process water U-Tube Liquid-to-Liquid Wide choice of materials for the process side.
Snow melt, radiant or glycol isolation Boiler water TB Brazed Plate Fit a strainer ahead of the unit.
Heat pump or small chiller duty Refrigerant or water TB Brazed Plate Follow the freezing protection steps in the manual.
Existing storage tank with a side opening Boiler water or steam Tank Heating Unit Double wall TAD or TBD for potable tanks.
Waterside economizer or large chiller isolation Tower or chilled water PF Plate and Frame, by quote Email both sides of the duty.

Sizing a Heat Exchanger

Three numbers start every selection: the load, the flows and temperatures on both sides, and the pressure drop each side can afford.

1. The load

For water, load in BTU/hr = 500 × GPM × temperature change in °F. For steam, load = steam flow in lb/hr × the latent heat of the steam, roughly 950 BTU per pound at low pressure. Glycol mixtures need the specific heat correction for the concentration.

2. Both sides

Each side has a flow, an entering temperature and a leaving temperature, and the load must balance between them. The closer the leaving temperature on the heated side gets to the entering temperature on the heating side, the more surface the unit needs.

Worked example: domestic hot water for a hotel. Heat 40 GPM of domestic water from 50°F to 140°F: load = 500 × 40 × 90 = 1,800,000 BTU/hr. With 180°F boiler water at a 20°F drop, the boiler side needs 1,800,000 ÷ (500 × 20) = 180 GPM. With low pressure steam at about 950 BTU per pound, the steam side needs about 1,800,000 ÷ 950 = 1,895 lb/hr. Because the heated side is potable, code will usually call for a Leak Guard double wall unit. Send us these figures and the allowable pressure drops, and Taco’s computer selection sets the shell diameter, bundle length and passes.

3. Pressure drop and limits

State the allowable pressure drop on each side so the selection fits the pumps you have; size the pumps with the HVAC pump calculator. Confirm the design pressure (150 psig standard on shell and tube) and the temperature (375°F standard), and for brazed plate confirm the fluids are compatible with stainless steel and copper or nickel.

Send Us the DutyHVAC Pump Calculator

Size Ranges by Family

The published range of each Taco family, and how many builds are available to order online.

Family Sizes Heating surface (sq ft) Max flow Builds online
U-Tube Liquid-to-Liquid 4-30 in shells 4.6-1,378 By selection 192
U-Tube Steam-to-Liquid 4-30 in shells 1-1,378 By selection 204
Leak Guard Liquid-to-Liquid 4-20 in shells 9.1-1,087.5 By selection 135
Leak Guard Steam-to-Liquid 4-20 in shells 9.1-1,211.8 By selection 140
TB Brazed Plate 0.63-3.9 in ports By plate count 696 GPM 246
Tank Heating Units 4-16 in, 12-120 in long By diameter and length By selection 339

From the Taco catalogs, submittals and the current Taco price sheets (200 Series, effective 11/03/25). Some longer bundles and the 18 and 20 in tank heating units are quoted on request. Each product page shows the full model table and the Taco documents.

What Sets Taco Heat Exchangers Apart

The design details behind each family, and why they matter on an installation.

Computer Selection

Taco selects each shell and tube unit by computer for the exact duty, so the shell, bundle length and passes match your flows and temperatures.

In-House Fabrication

All shell and tube fabrication is done in-house by Taco, to ASME Section VIII Division 1, with National Board and CRN registration available.

Free-Floating U-Tubes

The U-tube bundle expands freely with temperature, which protects the tube joints through heat-up and cool-down cycles.

Leak Guard Double Wall

Two walls between the fluids for potable water applications, with an enhanced heating surface on the steam-to-liquid models.

Material Choices

A wide choice of shell, head, tube and tube sheet materials, including cupro-nickel tubes, lets Taco match the unit to the fluids.

Compact Brazed Plate

TB units are gasket-free and a fraction of the size of a shell and tube unit, with copper or nickel brazing and a double wall TB16.

Lead-Free Certified

The U-tube and Leak Guard shell and tube units are certified and listed to NSF/ANSI 372.

Retrofit a Tank

Tank heating units bolt into an existing tank opening, turning a storage tank into a water heater without replacing the tank.

Complete the Hydronic System

Equipment that installs alongside a heat exchanger in the same mechanical room.

Taco 4900 Series air and dirt separator

Air and Dirt Separators

Keep air and dirt out of the heat exchanger with Taco 4900, AC, ACT and FlexBalance separators.

Taco TB5T brazed plate heat exchanger

Expansion and Buffer Tanks

Expansion tanks for each closed loop, and buffer tanks for chillers and heat pumps.

Taco tank heating unit

Circulator Pumps

Circulators for the primary and secondary sides and for hot water recirculation.

Taco Leak Guard double wall steam heat exchanger

Data Center Pumps and Systems

Pumps, boosters and tanks for data center facility and chilled water systems.

Every Taco heat exchanger on this page is genuine Taco equipment, factory-new in original packaging, with its Taco submittal and installation manual on the product page.

Why Buy Heat Exchangers from Watermain Supply

Engineering-Led Selection

We run the duty with Taco and confirm the model, surface and pressure drops before the order ships. Factory submittal on request.

The Whole Mechanical Room

Heat exchangers, separators, expansion and buffer tanks and pumps on one order, matched to each other.

Multi-Brand Honesty

We sell several HVAC and pump lines. If a different type or size is the better fit, we will say so.

Account Terms Available

Net-30 for qualified mechanical contractor, facility and municipal accounts. PO and credit applications handled in-house.

Freight Handled for You

Shell and tube and tank heating units ship by LTL freight. We arrange it and confirm the weight for the lift at delivery.

Houston and the Gulf Coast

Based in Houston, Texas, serving engineers and contractors across the Gulf Coast and nationwide.

Frequently Asked Questions

Common questions from engineers, contractors and facility managers selecting a heat exchanger.

What types of heat exchangers does Watermain Supply carry?

We supply Taco U-tube shell and tube heat exchangers for liquid-to-liquid and steam-to-liquid service, Leak Guard double wall shell and tube units, TB Series brazed plate heat exchangers and tank heating units. Gasketed PF Series plate and frame units are engineered to order and quoted on request.

What is the difference between a liquid-to-liquid and a steam-to-liquid heat exchanger?

A liquid-to-liquid unit transfers heat between two liquids, for example boiler water heating domestic water or a chilled water loop isolated from a process loop. A steam-to-liquid unit uses steam in the shell or tubes to heat water or another liquid, with steam inlet and condensate connections sized per model.

When do I need a double wall heat exchanger?

Choose a double wall unit where plumbing codes or the owner require two walls between the heating medium and potable water, typically when heating domestic water from boiler water or steam. Taco Leak Guard Series units use double wall copper tubes, and the steam-to-liquid version adds an enhanced heating surface.

Should I choose shell and tube or brazed plate?

Shell and tube U-tube units handle steam, large flows and high temperatures, accept a wide range of materials, and their U-tube bundles expand freely with temperature. Brazed plate units are far more compact and gasket-free, and suit hydronic, heat pump, snow melt and process loops with clean fluids. Plate and frame units, quoted on request, suit very large liquid duties and can be expanded or serviced plate by plate.

How is a heat exchanger sized?

Start with the load in BTU/hr. For water, load = 500 × GPM × temperature change in °F on each side. For steam, the steam flow in lb/hr times its latent heat gives the load. Send us both sides’ flows, entering and leaving temperatures and allowable pressure drops, and we return the Taco computer selection.

What pressure and temperature do Taco shell and tube units handle?

The U-tube and Leak Guard units are designed, constructed and tested to ASME Section VIII Division 1, with 150 psig standard on both the tube and shell sides and 375°F maximum standard. Tubes to 400 psig, shells to 250 psig and higher temperatures are optional.

Are Taco heat exchangers certified for potable water?

The Taco U-tube and Leak Guard shell and tube heat exchangers are certified and listed to NSF/ANSI 372, the lead content standard for drinking water system components.

What is a tank heating unit?

A tank heating unit is a U-tube bundle with a steel collar and head that bolts into the side opening of a storage tank and heats its contents with boiler water or steam. Taco builds them in 4 to 16 in diameters and 12 to 120 in bundle lengths, in single wall copper or cupro-nickel, or Leak Guard double wall copper.

What warranty comes with Taco heat exchangers?

TB Series brazed plate units are covered for 1 year from start-up or 18 months from shipment, whichever comes first, under Taco’s limited warranty. For the shell and tube and tank heating lines, ask us and we will confirm the current Taco terms with your quote.

How are heat exchangers shipped?

Smaller brazed plate units ship by parcel or freight depending on plate count. Shell and tube units and tank heating units ship by LTL freight; we arrange the shipment and confirm the weight so you can plan the lift at delivery.

Ready to Select Your Heat Exchanger?

Send both sides’ flows, entering and leaving temperatures and allowable pressure drops. We reply with the Taco selection, lead time and freight.

1-888.510.4036 Selection Guide Email sales@watermainsupply.com Request a Quote
Technical data on this page is taken from Taco product literature and is subject to change by the manufacturer. Confirm against the current installation manual before specifying.
Taco and Leak Guard are trademarks of Taco, Inc., used here for product identification only.
Watermain Supply is a DBA of E4 Industrial LLC, an independent industrial supplier based in Houston, Texas.