CUP-BB2 MTBR significantly improved0 pages

CASE STUDY
CUP-BB2 MTBR SIGNIFICANTLY IMPROVED
Ingersoll-Rand JVL
- mechanical upgrade
Industry:t
Industrial - paper mill
Region:t
Americas
Territory:t
USA
Category:t
Mechanical design upgrade
API Type:t
BB2
ClydeUnion Pumps Aftermarket Technical Services
team has experience across a range of services
on critical rotating and reciprocating equipment to
improve operational safety, reliability and efficiency. The
mechanical upgrade of the Ingersoll-Rand 8 JVL pumps
for the industrial market is one of our success stories
documented in our library of case studies. These case
studies highlight the requirement from the customer,
how we achieved the goal and the process we followed
to deliver the improvements.
Image left: Complete pump
Situation
The project included a mechanical upgrade on an Ingersoll-Rand
Analysis of the pump was completed to try and determine the
8 JVL to extend the reliability and Mean Time Between Repairs
cause of the broken shaft under the impeller. Calculations of the
(MTBR). The shaft was found sheared under the impeller fit,
first and second dry natural frequencies were done on the original
as indicated by rotation of continuous key by 30°. The impeller
pump (see table 1 overleaf). The results show that the pump’s first
was found with a crack in the hub of the impeller at the keyway
and second dry natural frequencies were running quite close to the
and the impeller wear rings were also rubbing 360° around.
x 1 and x 2 running speed. When estimating the affects of the worn
Some case damage was found from erosion and rubbing of the
packing and wear rings, the pump was operating at critical speed.
impeller.
Challenge
▪▪ Analysis of the rotor will help to determine the cause of failure
of the shaft and impeller, and help to define the parameters
for the new shaft and bearing housing
▪▪ Upgrade of old style sleeve bearings to ball-ball construction
was also required to make the rotor more rigid
▪▪ Upgrade from packed pump to mechanical seals
Top half of casing removed to see condition of the rotor.