The Parker CPI / A-LOK Reducing Union (HBZ / RU) joins two fractional tubes of different outer diameters. It comes in 23 size combinations with tube outer diameters from 1/16" to 1". CPI uses a single ferrule and A-LOK a double ferrule.
| Type | Reducing union: joins two tubes of different outer diameters |
| Part Numbers | CPI 2-1 HBZ, A-LOK 2RU1 ~ CPI 16-12 HBZ, A-LOK 16RU12 |
| Size Numbers | Size numbers in the part number are in sixteenths of an inch (for example 1/2" tube = 8) |
| Connection Method | CPI: single ferrule / A-LOK: double ferrule |
| Material | 316 stainless steel (heat code traceable) is standard / Other materials: steel, brass, aluminum, nickel-copper, Hastelloy C, Alloy 600, titanium, 6Mo, Incoloy 625 and 825 |
| Material Codes | Material code added to the end of the part number after a hyphen: B brass / SS or 316 = 316 stainless steel / S steel / A aluminum / M Alloy 400 / HC Hastelloy C-276 / IN Alloy 600 / SS20 Carpenter 20 / 6MO 6Mo / 625 / 825 / T titanium |
| Sizes (inches): Tube O.D. by CPI Part Number (A-LOK Part Number) | 2-1 HBZ (2RU1): tube O.D. 1/8" x 1/16" / 3-1 HBZ (3RU1): tube O.D. 3/16" x 1/16" / 3-2 HBZ (3RU2): tube O.D. 3/16" x 1/8" / 4-1 HBZ (4RU1): tube O.D. 1/4" x 1/16" / 4-2 HBZ (4RU2): tube O.D. 1/4" x 1/8" / 4-3 HBZ (4RU3): tube O.D. 1/4" x 3/16" / 5-2 HBZ (5RU2): tube O.D. 5/16" x 1/8" / 5-4 HBZ (5RU4): tube O.D. 5/16" x 1/4" / 6-1 HBZ (6RU1): tube O.D. 3/8" x 1/16" / 6-2 HBZ (6RU2): tube O.D. 3/8" x 1/8" / 6-4 HBZ (6RU4): tube O.D. 3/8" x 1/4" / 6-5 HBZ (6RU5): tube O.D. 3/8" x 5/16" / 8-2 HBZ (8RU2): tube O.D. 1/2" x 1/8" / 8-4 HBZ (8RU4): tube O.D. 1/2" x 1/4" / 8-6 HBZ (8RU6): tube O.D. 1/2" x 3/8" / 10-6 HBZ (10RU6): tube O.D. 5/8" x 3/8" / 10-8 HBZ (10RU8): tube O.D. 5/8" x 1/2" / 12-4 HBZ (12RU4): tube O.D. 3/4" x 1/4" / 12-6 HBZ (12RU6): tube O.D. 3/4" x 3/8" / 12-8 HBZ (12RU8): tube O.D. 3/4" x 1/2" / 12-10 HBZ (12RU10): tube O.D. 3/4" x 5/8" / 16-8 HBZ (16RU8): tube O.D. 1" x 1/2" / 16-12 HBZ (16RU12): tube O.D. 1" x 3/4" |