Support, Process & Refining Tube
Centrifugally cast tubes such as reformer, cracking and catalyst tubes for high-temperature and high-pressure applications are manufactured in accordance with the general requirements of ASTM A608. Selected alloys from DIN EN10295 and a number of unassigned/proprietary alloys are also used.
Tubes are supplied as cast, partially machined or fully machined. Machining of outer tube surfaces involves turning while inner surfaces are pull bored.
Support tubes or “stanchions” are normally cast, weld preps machined and Tig welded together on in-house automatic and semi-automatic orbital and rotating welding machines. The supports usually have holes for the supporting bars or pins – these are either drilled or plasma cut on Steloy’s in-house machining and plasma cutting equipment.
The current Steloy range offers sizes up to 830mm in diameter and 5 500mm long. Smaller diameter tubes can be longer, i.e. 4 500mm long, with outer diameters ranging from 80mm to 200mm, and inner diameters as small as 32mm. The surface finish after pull boring is typically 1.6 to 3.2μm. The variation in dimensions is within the tolerances indicated in section 8 of ASTM A608 and complies with the requirements of ASTM A530.
Product marking, certification and pressure testing are conducted in accordance with mutually agreed procedures. Provision has been made to conform with supplementary requirements of ASTM A608 through various analysis, testing and examination procedures.
Centrifugally cast tubes are produced in accordance with the general requirements of ASTM A608. Selected alloys from DIN EN 10295 and a number of unassigned/proprietary alloys are also produced.
| Specification of reference |
Alloy |
Remarks |
|
ASTM A608 |
HC30; HD50; HE35; HF30; HH 30; HH33; HI35; HK40; HK30; HL30; HL40; HN40; HT50; HU50; HW50; HX50 |
|
|
API 560 |
ASTM A608 HK40 |
|
|
Unassigned |
HP45; HP45 Nb; HP45 Nb micro |
Modifications of 1.4852 |
|
DIN EN10295 |
G X 40 Ni Cr Si Nb 35-26 |
1.4852 |