Flowserve ISC2-PP Dual Pressurised Mechanical Seal

The Flowserve ISC2-PP is a dual pressurised cartridge mechanical seal designed and tested to API 682 4th Edition Category 1, Arrangement 2 (dual pressurised) requirements — the seal specification that Saudi ARAMCO and SABIC mandate in pump procurement packages for hydrocarbon services above the auto-ignition threshold, toxic services, and environmentally sensitive duties where zero atmospheric emission is required. The ISC2-PP-2.500 model designates a 2.500-inch (63.5 mm) shaft size cartridge, covering the majority of API 610 OH2 and BB1 pump frames used in ARAMCO and SABIC processes. The integral cartridge design pre-sets the working length, spring compression, and face alignment at the factory, eliminating field measurement and assembly errors that are the primary cause of seal failures in installations by contract maintenance crews during ARAMCO turnarounds.

The ISC2-PP operates with a pressurised API Plan 53 barrier fluid system — typically a clean, compatible fluid maintained at 1.4 bar above the process pressure — creating an inward pressure differential at the process-side seal faces that prevents any leakage of process fluid to atmosphere even in the event of process-side seal face wear or failure. The outboard seal contains the barrier fluid, and only the clean barrier fluid is released to atmosphere in the event of outboard seal failure, which is the safe failure mode required by ARAMCO HSE standards for hydrocarbon vapour control at GOSPs and refineries. The ISC2-PP's silicon carbide versus silicon carbide primary face combination is selected for its resistance to dry running, particulate abrasion from produced water solids, and flash evaporation damage from light hydrocarbons — the three most common seal failure mechanisms in ARAMCO Eastern Province pump installations.

Flowserve's ISC2 product line is explicitly listed on the ARAMCO Approved Vendor List (AVL) for mechanical seals under the API 682 category, and the ISC2-PP is the most widely specified Flowserve seal in ARAMCO pump procurement packages for crude oil booster, gas condensate transfer, produced water injection, and NGL transfer services. ARAMCO's engineering standard SAES-A-004 Table 1 designates API 682 Arrangement 2 (dual pressurised) as the required seal arrangement for Group I (light hydrocarbon) and Group II (crude and condensate) pump services, and the ISC2-PP satisfies this requirement across the full temperature range of -40°C to +260°C that encompasses ARAMCO's cryogenic LNG service through high-temperature crude stabilisation service. SABIC Olefins and Aromatics affiliates at Jubail also specify the ISC2-PP for ethylene feed pumps and other critical polymer-precursor services where unplanned seal failure causes process shutdown and product loss.

Razz Middle East maintains an extensive consignment stock of ISC2-PP cartridges in 2.000, 2.125, 2.250, and 2.500-inch shaft sizes, with Plan 53A/B barrier fluid reservoirs, pressure gauges, and tubing kits as complete replacement packages. Our seal application engineers provide barrier fluid compatibility review, face combination selection for specific process conditions, and on-site installation training for ARAMCO and EPC contractor maintenance crews. We also supply Flowserve's complementary SCT seal support system — the API 682 Plan 53B self-contained pressurised reservoir — as a factory-assembled and tested unit for ARAMCO GOSPs where centralised barrier fluid systems are not available.