SERVICE TRAINING
Service Manual
37
Rock Valve
Welding Procedures-SAIE 5312
Subject:
SAIE STANDARD
No. :
Date :
By :
Sheet :
SAIE - 5312
12-10-92
Rev :
TA
1 of 1
WELDING PROCEDURES - ROCK VALVE HOUSING
For general welding on the rock valve housing, Schwing Germany recommends a
UTPO68HH DIN 1736, S-NiCr 19 Nb, material number 2.4648. An equivalent American
electrode must have the following physical and chemical properties:
The parts to be welded must be very clean. Preheat the area to be welded to 250 to 300 C
(480 to 570 F). Incline the electrode slightly and weld with short arcing. To prevent final
crater cracks, fill up the crater as well as possible and lift-off the arcing at the side. To
prevent cracking, we recommend placement of the casting into a preheated oven and letting
it cool from 600 F to room temperature over 12 hours. If an oven is not available in your city,
you can try to let the weld cool slowly under an asbestos blanket, an aluminum cover, or
sand.
Alloy by % Weight Permissible Additives
Ni - at least 67 C - 0.1%
Cr - 18.0 to 22.0 S - 0.015%
Mn - 2.0 to 6.0 Co - 0.1%
Nb - 1.5 to 3.0 Si - 1.0%
Cu - 0.5%
Ti - 0.5%
Fe - 4.0%
Mo - 2.0%
other elements total - 0.5%
Melting range - approx. 1400 C (2550 F).
Nb is Niobium and it can be replaced by Ta (Tantalum)
Preheat the electrodes for 2 to 3 hours at 250 to 300 C (480 to 570 F)
The electrode must be high Ni and Cr content and high elongation. For
example, Huntington INCONEL #82 wire, (AWS-ERNICRS) and Huntington
INCO weld A, for
1
/
8
" (Schwing Part#30352281) or
3
/
32
"(Schwing
Part#30352282) electrode AWS-ENICRFE2 or equivalent.
To Next Page
Loading...