VAM Book - VAM Services

Table 2 applicable only for:
⇨ VAM TOP casing (5" and above) mixed with VAM TOP HT
⇨ VAM TOP casing (5" and above) mixed with VAM TOP HC
⇨ VAM TOP HT mixed with VAM TOP HC
⇨ VAM TOP HC with VAM TOP HC
⇨ VAM TOP HT mixed with VAM TOP HT (see special recommendations
for VAM TOP HT in section 2.9.4.5).
Grade difference (KSI)
Weight difference (1)
0 10 20 >20
0
1
2
>2
NOTE: If the connection type is not listed above then contact VAM Services
for advice!
2.9.4.2 Terms description.
Before mixing interchangeable connections first verify if a torque can be
determined. Even connections which are interchangeable may not always
be mixed as a large difference in weight or steel grade could induce derating
on performance and/or torque problems.
2.9.4.3 Difference in weights and grades.
For each diameter exits different weights. For example in 7” you have 23
lb./ft. 26 lb./ft. 29 lb./ft. 32 lb./ft. 35 lb./ft. 38 lb./ft.
When this document mentioned difference of 2 weights is acceptable means
for example 7” 26# L80 VAM TOP can be mixed with 7” 32# L80 VAM TOP.
Note: The reference table shall be the weight in the technical data table in
the connection section.
When this document mentioned grade difference of 30 ksi is allowed. Means
for example 7” 26# L80 VAM TOP and 7” 26# P110 VAM TOP can be mixed.
(110 ksi -80 ksi = 30ksi)
Errata
24 th August 2011 xii