ASTM B111 C23000 Red Brass Tube for Condensers and Water Service

What Is C23000 Red Brass

ASTM B111 C23000 is red brass, an 85/15 copper zinc alloy also designated CDA 230, C230 or simply 230 brass. It is one of the most durable metals available for commercial water pipe in the practical price range, and it is chosen wherever resistance to dezincification and season cracking is required together with moderate strength and good retention of spring properties. The alloy is specified for underground service lines because it offers strong corrosion resistance to all types of potable water, and it is also supplied as condenser and heat exchanger tube to ASTM B111 and ASME SB111.

The high copper content is the key to its behaviour. With 84 to 86% copper, the alloy is metallurgically closer to copper than to a standard brass, so it retains much of the noble electrochemical character of copper while having usefully higher strength than pure copper. The European designation for the same composition is CuZn15, which reflects the roughly 15% zinc balance.

Chemical Composition

Both the lead and iron limits are tight, which keeps the microstructure clean and helps the alloy hold its corrosion resistance in aggressive water. A low lead content is also relevant to modern drinking water projects, where many specifications require low lead levels in wetted components.

Tube and Related Product Specifications

Because the alloy is available in bar, plate, sheet, strip, wire, pipe and tube, a single material grade can be used through an entire assembly. That reduces the risk of galvanic mismatch between tube, tubesheet and fittings, which is a common source of premature failure in mixed alloy condensers.

Dezincification and Season Cracking Resistance

Dezincification is the selective leaching of zinc from brass, leaving a porous copper residue that has almost no strength. It is the dominant failure mode of ordinary yellow brass in stagnant or slowly moving water. Red brass resists it for two reasons: the zinc level is low enough that the alloy stays in the single phase alpha region, and the high copper content suppresses the electrochemical driving force for zinc dissolution. Season cracking, the stress corrosion cracking of brass in the presence of ammonia and residual tensile stress, is likewise strongly suppressed in the high copper brasses.

In practical terms this means C23000 tube can be installed in underground service lines, water works and industrial cooling water systems with a much lower risk of the sudden loss of wall thickness that characterises dezincified tube. Where the water chemistry is unusually aggressive, the alloy is frequently paired with inhibited grades or with a slight increase in wall thickness as a design allowance.

Typical Uses Across Industries

Industrial: heat exchanger shells and tubes, condenser tubes, radiator cores, flexible metal hose, pump cylinder liners and instrument tubing

Plumbing: fittings, pipe service lines, pipe nipples, pump lines, J-bends and traps

Electrical: sockets, screw shells, conduit, rotor bars and AC motor components

Architecture: etched parts, weather strip, trim and decorative architectural metalwork

Fasteners: fasteners and eyelets, where moderate strength and corrosion resistance combine

Builders hardware: kick plates and other abrasion resistant fittings

Fire protection: fire hose couplings and associated screwed fittings

Tubes for condensers and heat exchangers are supplied seamless, welded or as U-bend bundles depending on the specification called for by the bundle drawing, and the alloy can be supplied in the annealed temper for bending or in a harder temper where stiffness and wear resistance are wanted.

Tube is produced by extrusion and cold drawing followed by controlled annealing, with chemistry verified by spectrometer analysis on each heat. Dimensions are checked against the order, and eddy current testing plus pressure testing is applied to tube destined for heat exchanger service. Bar and rod are supplied from 3 mm to 300 mm diameter in lengths from 1000 mm to 4000 mm, sheet and plate from 0.3 mm to 50 mm thickness, strip from 0.05 mm to 3.0 mm thickness and wire from 0.05 mm to 12 mm diameter. Tube is supplied with outside diameter from 6 mm to 159 mm, wall thickness from 0.5 mm to 5 mm and straight lengths from 1 m to 6 m or coils up to 50 m.

Certification covers the standard requirements of the ordered specification, together with dimensional and non destructive test records, so that the material can be released to a pressure equipment or marine project without further chemistry checks at site.

FAQ About C23000 Red Brass Tube

Q: What is the difference between red brass C23000 and yellow brass?
Red brass contains 84 to 86% copper with about 15% zinc, while yellow brass typically contains around 65% copper with 35% zinc. The higher copper content of C23000 makes it far more resistant to dezincification and season cracking in water service.

Q: Is C23000 suitable for underground water service lines?
Yes. The grade is specified for underground service lines because it offers the strongest corrosion resistance to potable waters, which is exactly the environment where dezincification of ordinary brass would otherwise cause premature wall loss.

Q: Which specification applies to condenser tube in this grade?
Condenser and heat exchanger tube is ordered to ASTM B111 or ASME SB111. Seamless tube is covered by ASTM B135, welded tube by ASTM B543 and ASTM B587, finned tube by ASTM B359 and U-bend tube by ASTM B395.

Q: What is the European equivalent of C23000?
The European designation for the same composition is CuZn15, reflecting the balance of roughly 15% zinc. The material is also known by the CDA 230 and C230 designations used in North American practice.

Q: Can it be soldered and brazed?
Yes. Red brass solders and brazes readily because of its high copper content, and it is commonly joined to copper tube and brass fittings in plumbing and heat exchanger assemblies without special procedures.

Q: What sizes are produced?
Tube is available with outside diameter from 6 mm to 159 mm, wall thickness from 0.5 mm to 5 mm and length from 1 m to 6 m straight or coils up to 50 m. Bar and rod cover 3 mm to 300 mm diameter and sheet and plate cover 0.3 mm to 50 mm thickness.