CUP-VS60 pages

CASE STUDY
VERTICAL TURBINE UPGRADE
VM32 upgrade - discharge
elbow + bearing modifications
Industry:t
Oil + Gas - chemicals
Region:t
Europe
Territory:t
France
Category:t
Site fault investigation
API Type:t
VS6
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 design
upgrade of the VM32 for the oil and gas 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: Vespel® bearing
Situation
Challenge
Our customer had previously independently repaired the
The gland ring outlets on the discharge elbow were not sufficient
discharge headpiece pipe on a vertical chemical pump as it
to evacuate the liquid that passes around the head shaft. To solve
had cracked several times. Due to the complexity and difficult
this problem a third outlet had been added to the discharge elbow,
accessibility of the welding, plus relative fragility of the assembly,
but this modification has weakened the lower part of the discharge
the consultation between ClydeUnion Pumps and the customer
elbow. This weakness leads to a crack of the discharge elbow.
resulted in agreement to re-design the whole discharge elbow.
Solution
The solution was to re-design the discharge elbow and separate
it in two parts, the elbow itself, above the support surface, and a
suction spool under. ClydeUnion Pumps also made the decision
to change the former bearings material to a Vespel® CR6100
(carbon fibers in PTFE resin matrix). Indeed the corrosive nature of
the liquid pumped increases the hydraulic clearances of the pump.
Failure area
3rd additional outlet
These gaps generated vibrations that contribute to the destruction
of the discharge elbow. The choice of Vespel® CR6100 was done
for its excellent resistance at wear and abrasion and chemical
2 gland ring outlets
Head shaft place
compatibility.