Revamps 2026 Issue

(see Figure 2 ), especially severe wear on the slide valve gate. Excessive wear around the stem and/or guides may indi- cate issues with the packing purge or exces- sive use of the guide purge. Erosion issues should be reviewed with the slide valve vendor to determine whether the valve can be refurbished or should be replaced. Sticking issues during the run may also indi- cate issues with packing purge, guide clearance, or wear.

Figure 2 Severely eroded slide valve gate

wear possibly due to misdirection. The nozzle preparation along with the preparation procedure should be noted in the turna- round report. Riser The feed riser often has refractory requiring repair. If the damage is significant from the prior turnaround, replace - ment of the riser may be recommended for the next turn- around. In addition to the feed nozzles, the riser may also include lift steam and emergency steam nozzles, recycle nozzles, pressure nozzles, and guarded thermowells. Lift steam and emergency steam at the riser base are often subject to erosion and damage. Any specialised nozzle distributors should be procured prior to the turnaround. Any issues with pressure or tem- perature indication should be included in the turnaround scope. Nozzles should be inspected for plugging due to coking or other contaminants. Damage to thermowell guards should be noted. If the damage has been significant, consider a review of an alternate design. Reactor Today’s reactors function as housing for riser termination Figure 3 Riser wye – steam chest

After the slide valve has been installed, it is recom- mended to mark where the plate edge meets the overhang (mark of actuator) and note the position in the control room. Also, record when the valve is fully open. Verify the time required to fully close the valve and compare it with the design criteria. The valve hydraulic system should also be serviced, preferably by the hydraulic skid vendor. Any issues with hydraulic oil condition or servo should be noted for possible increased monitoring (usually by the hydraulic skid vendor). Prior to unit start-up, the slide valve packing purge should be checked for proper operation, including ensuring that the restriction orifice is installed and open, and verifying the purge flow (usually from the bleeder). The purge meter flow should also be verified. Any guide purge piping should be disconnected but ready if needed. Inspect all taps and ensure aeration and pressure taps are all clear. All ROs should be inspected (pulled, verify opening, replace as needed). Carefully inspect the wye/J bend area for unusual wear (see Figure 3 ). Identify areas of excessive wear for repair and upgrades in future turn- arounds. Note areas with significant refractory repair and assess if replacement is justified. Feed nozzles Riser feed nozzles are critical to achieving optimal and reli- able unit performance. These nozzles are subject to wear, particularly at the tips, and should be repaired at every turnaround. Feed nozzle components are long lead items – spare tips and other critical components should be stocked in advance, as recommended by the nozzle technology provider and informed by experience from the previous turnaround. Note if there were issues removing the nozzles from the prior turnaround and any changes to the nozzle preparation. If there are issues, recommend reviewing the feed noz- zle preparation prior to nozzle insertion (see Figure 4 ). Damage to the insert may also need to be addressed. Feed nozzles should be inspected in the riser prior to removal for plugging, coke around or near the nozzles and refractory

Figure 4 Feed nozzle measurement prior to installation

Revamps 2026