boiler feed pump recirculation valve problem

Performance of the BFPs after rectification of CCI Drag Make Recirculation valves passing

Prepared by

KODANDAPANI VUDUGUNDLAADE/TURBINE MAINTENANCE/RTPP

,

RC Valve Details

Type : CCI Drag 100DR 4X4 GLOBE VALVEPr class 2500 ANSI

Design pr -320kg/cm2, Temp-180CMax seat leakage-5cc/min

valve Trim -24 stage disc stack

MAINTAIN LIQUID LUBRICATION INSIDE PUMP INTERNALS

MAINTAIN MINIMUM FLOW(125T) THROUGH PUMP TO AVOID FLASHING OF WATER

AVOID PUMP SEIZURE

VALVE OPENS AT 100 T BFP SUCTION FLOW VALVE CLOSES AT 220T BFP SUCTION FLOW

IMPORTANCE OF RECIRCULATION VALVE

NRV

At 6 mts

LOCATION OF VALVE

At 21 mts

FEED WATER INLET TAPPING FROM BFP DISCHARGE

FEED WATER OUTLET TO DEAERATOR

RC VALVE INTERNALS

HIGH FEED FLOWHIGH MOTOR AMPERAGE

PUMP VIBRATIONSDAMAGING OF NRV IN RC LINE

OUTAGES OF PUMP

PROBLEMS FACED

Dismantled all RC valvesFound damaged Seat Ring & Plug

Replaced with new one & Reassembled

Spare parts usedPlug assembly ,Seat ring ,Guide

bushing balance seal and soft goods.

WORKS ATTENDED

DAMAGED PLUG

DAMAGED PORTION

DAMAGED SEATDAMAGED PORTION

FLEX GASKET

SEAT RING

PLUG ASSEMBLY

GUIDE BUSHING

BALANCE SEAL

STEM

PLUG

BONNET METAL SEAL

DISK STACK

BALANCE SEAL

FLEX GASKET

SET OF RC VALVE INTERNALS

PERFORMANCE OF PUMPSAFTER RECTIFICAION AT FULL LOAD

BFP-5A BFP-5B BFP-5CFEED FLOWT/HR

CURRENTAMPS

FEED FLOWT/HR

CURRENTAMPS

FEED FLOWT/HR

CURRENTAMPS

PREVIOUS

364 306 370 315 355 310

PRESENT 342 297 332 292 344 300

CURRENTSAVING

9 A 23 A 10 A

ENERGY SAVING Per Day

2099 KWH 5363 KWH 2322 KWH

SAVING COST/Day @ Rs 5/-

10,494.00 26,818.00 11,658.00

REDUCTION IN POWER CONSUMPTION

REDUCTION IN FEED FLOW

REDUCTION IN PUMP VIBRATIONS

REDUCTION OF NOISE IN RC PIPE LINE

ELIMINATING DAMAGING OF NRV

RESULTS

Purchase of Spares including service chargesRs 40 Lakhs

Average Energy Loss/Year in RupeesRs 120 Lakhs

Pay Back period is with in 4 Months

Guarantee period of spares is one year

COST ANALYSIS

CONCLUSIONThe BFP recirculation valve is one of the most severe duty valve in the plant.

If this valve does not perform up to expectations, it can cause severe pump damage, degraded unit performance or even bring a unit offline

THANK YOU