In the Formosa Mailiao Plant, Scenic successfully resolved leakage issues in the SIHI^® vacuum pump by implementing the APD^®302™ cartridge seal and transitioning to the API piping plan53A.

The former use of component wedge seals couldn't withstand the significant vibrations generated during the vacuum pump operation, resulting in severe wear and subsequent leaks. With the adoption of APD^®302™, substantial improvements were achieved, significantly mitigating wear problems and extending the seal lifespan to a 3-year maintenance cycle.

PRODUCT: APD302

WORKING CONDITION

• Industry: Chemical & Petrochemical 
• Factory: Formosa Mailiao Plant, M510 Caustic Soda Plant 
• Equipment Number: SIHI^® Vacuum Pump B153 
• Temperature: 47°C 
• Process Fluid: 13% Saline Solution + 87% Chlorine Gas 
• Rotating Speed: 1000RPM 
• Shaft Diameter: 108MM 
• Sealing Type/Piping Plan (Before): Back-to-Back Unbalanced Wedge Seal/ Plan 54 
• Sealing Type/Piping Plan (After): Dual Cartridge Seal APD^®302™/ Plan 53A

BEFORE

• Piping Plan: API Piping Plan 54
• Seal Type: Wedge seal with multi springs and unbalanced back-to-back structure
• Usage Cycle: 1 to 2 months
• Failure Analysis:
• Springs breakage and wear on the wedge sleeve
• The vacuum pump vibrates significantly, creating substantial amplitude during operation, leading to increased axial displacement of the wedge seal and wear on the sleeve.
• The unbalanced wedged structure can only withstand unidirectional pressure.
• Difficulties in disassemble and assemble the wedge component seal, resulting in high maintenance costs.

AFTER

• Piping Plan: API Plan53A
• Seal Type: Dual cartridge seal APD^®302™, a balanced back-to-back structure
• Starting Date: AUG 2009
• Usage Condition: Extended lifespan requiring disassembly the seal for maintenance once every 3 years. 
• The cartridge type allows for easy disassembly, significantly reducing maintenance costs.

SEALING SOLUTION & HIGHLIGHT

• Cartridge structure allows easy disassembly and maintenance.
• Patented baffle ring optimizes cooling effect.
• A back-to-back integral structure with shared springs stabilizes the sealing faces.
• The balanced structure achieves advanced sealing effect by balancing the pressure from pump's vibrations and the inner pressure of the seal.
• Outer pumping ring promotes heat exchange efficiency.
• Self-alignment capability tolerates seal run-out up to ±0.5mm.