TECTULby IMR

Fluid conveyance · Copper tube

TECHNICAL DATA SHEET

FT-TC-TUB-CU-001

Issue date: July 22, 2026 · Rev. 001

Check the current version

VT-156437 (K) · VT-156440 (L) · VT-156441 (M) · drawn-temper rigid copper, 6 m lengths

1. TECHNICAL SPECIFICATIONS

ASTM B88-22 Types K, L and M share the same outside diameter for each size and differ only in wall thickness: K is the heavy wall, L the intermediate and M the light one. All three therefore install with the same capillary solder fittings (ASME B16.22-2021), and selection is driven by pressure, service and the applicable code. The nominal diameter is 1/8 in smaller than the actual outside diameter: a “1/2″” tube measures 5/8 in (15.88 mm) outside.

General specifications

Dimensions by type (ASTM B88 / CDA Tables 2a-2c)

Theoretical weights calculated by CDA from nominal dimensions. “—”: size not defined in the standard for that type. Published range by type and diameter per the product page: Type K is published from 1/4″ to 3″, Type L from 1/4″ to 3″ (4″ and 6″ on request) and Type M from 1/2″ to 2-1/2″; confirmed when quoting.

2. ENGINEERING CALCULATIONS

The allowable internal pressure of the tube is calculated with the ASME B31 pressure piping code formula as applied by the CDA Copper Tube Handbook. For copper, the code allows a corrosion allowance C = 0 because of the material's corrosion resistance. Every value used is declared — nothing is silently assumed:

P = 2 · S · t_min / (D_max − 0.8 · t_min)

Worked example — Type L 2″ drawn temper

1. Nominal wall: t = 0.070 in (1.78 mm); OD: 2.125 in (53.98 mm) — ASTM B88 / CDA Table 2b.
2. t_min = 0.9 × 0.070 = 0.063 in (1.60 mm); D_max = 2.125 + 0.002 = 2.127 in (54.03 mm).
3. P = 2 × 10,300 × 0.063 / (2.127 − 0.8 × 0.063) = 625 psi ≈ 43.1 bar — matches the value published by CDA (Table 3b).

S(T) — allowable stress by temper and temperature (ASME B31 / CDA)

Tube allowable pressure by type, temper and diameter at ≤100 °F (CDA Tables 3a-3c)

¹ Type M is not normally supplied annealed: CDA publishes its annealed column as guidance for when drawn tube is brazed. The annealed rating also applies to drawn tube joined by brazing or welding, because the heat anneals the affected zone (see joint section). At other service temperatures the pressure scales proportionally with S(T) from the table above. These are tube values: the system pressure is limited by the joint whenever its rating is lower — with soft solder it almost always is (next section).

3. THE JOINT GOVERNS: SOLDER-JOINT PRESSURE RATING BY ALLOY AND TEMPERATURE

The pressure rating of a soldered copper system is the lower of the tube allowable pressure and the joint rating, and with soft solder the joint almost always governs. Example: a 2″ Type L drawn tube is rated 625 psi (43.1 bar), but its 50-50 soldered joint is rated 175 psi (12.1 bar) at ≤100 °F and only 90 psi (6.2 bar) at 200 °F: the line is limited to 90 psi, 14% of what the tube withstands. Ratings per ASME B16.22-2021 (Table I-1) for pressure fittings, reproduced in CDA Copper Tube Handbook, Table 4; filler alloys per ASTM B32.

Joint with alloy Sn50 (50-50 tin-lead)

Potable water restriction: solders with more than 0.2% lead —including 50-50— are prohibited in potable water systems (CDA Table 4 note, per the 1986 amendment of the U.S. Safe Drinking Water Act; modern sanitary practice follows the same criterion). For potable water use lead-free fillers such as Sb5.

Joint with alloy Sb5 (95-5 tin-antimony)

Brazed joint

With filler metals melting at 593 °C (1,100 °F) or above —BCuP copper-phosphorus or BAg silver alloys, AWS A5.8— the joint equals or exceeds the tube, but the heat of the operation anneals the drawn tube in the heat-affected zone: the applicable rating becomes that of annealed tube (the “annealed” columns of the calculation section). For the 2″ Type L example: 364 psi (25.1 bar) brazed, versus 625 psi for drawn tube with a mechanical joint and 175 psi with 50-50 soft solder at ≤100 °F.

Saturated steam: maximum 15 psi (1.0 bar) with soft solder and 120 psi (8.3 bar) with brazing, for all diameters (CDA Table 4).

4. TEMPER AND FORM: DRAWN (H58) VS ANNEALED (O60)

ASTM B88-22 defines the drawn temper H58 (cold-drawn, “hard”) for straight lengths and the annealed tempers O60/O50 (“soft”) for coils. This sheet covers rigid H58 tube in 6 m lengths; annealed coil tube is the Flexible copper tube reference of the catalog.

Temper matters because it sets the allowable stress: 71.0 MPa (10,300 psi) drawn versus 41.4 MPa (6,000 psi) annealed at ≤100 °F — annealed tube takes 42% less pressure with the same wall. And temper is not permanent: brazing or welding locally anneals drawn tube, so design must use the annealed rating in brazed systems (CDA Copper Tube Handbook, p. 12).

• Drawn (H58): straight lengths, higher allowable pressure, rigidity and better appearance in exposed runs; joined with capillary solder or mechanical fittings.
• Annealed (O60): coils, bendable by hand or with a bender, ideal for service lines and winding runs without fittings; lower allowable pressure.

5. SERVICE COMPATIBILITY BY TYPE

Admissible service depends on the type: K and L cover every application in the table; Type M is excluded from gas and compressed air per CDA. The local code and the authority having jurisdiction always govern.

Potable water: all three types qualify; the restriction is at the joint —filler with ≤ 0.2% lead, i.e. no 50-50 alloy (see joint section).

Refrigeration and air conditioning (refrigerant lines): these use ACR tube per ASTM B280 —sized by actual OD, factory dehydrated and sealed—, not B88 tube: that is the Flexible copper tube reference of the catalog. The rigid B88 tube of this sheet does serve HVAC hydronic lines (chilled/hot water).

Medical gases: NFPA 99 (Health Care Facilities) requires Type K or L tube cleaned for oxygen service per ASTM B819, brazed with inert-gas purge. The standard B88 tube of this sheet does not substitute certified B819 tube.

6. THERMAL EXPANSION

The average coefficient of linear expansion of copper is 9.4 × 10⁻⁶ in/in·°F between 70 °F and 212 °F (21–100 °C), equivalent to 16.9 × 10⁻⁶ m/m·K (CDA Copper Tube Handbook). It is slightly higher than iron and steel and considerably lower than plastics, per the same source.

ΔL = α · L · ΔT

Worked example: a 30 m line going from 20 °C to 60 °C (ΔT = 40 K) grows ΔL = 16.9 × 10⁻⁶ × 30,000 mm × 40 = 20.3 mm. That movement must be absorbed with expansion loops or offsets, changes of direction or compensators —not by rigidly anchoring the tube between fixed points—; CDA publishes loop radii and offset lengths in its Table 8. On vertical lines the CDA practice is to support roughly every story (about 10 ft), with sliding sleeves at intermediate levels.

7. Application notes

8. Technical notice and limitation of liability