Sealing solutions for continuous processes

A chemicals company in the Middle East uses the refrigerant R134A-Freon in the production of toluene diisocyanate (TDI). Shortly after the refrigeration plant is commissioned, a magnetic coupling pump fails. Quick help was called for, EagleBurgmann delivered the O-ring seal H75VN with DiamondFace.

Operating conditions: d₁ = 90 mm (3.543”), p₁ = 12.4 barg (179.8 PSIG), t = 45 °C (113 °F), vg = 6.5 m/s (21.3 ft/s)

Read on for the entire case study.

The El Dorado Chemical Co. in Arkansas, USA, uses metal expansion joints in the plant for production nitric acid.

Operating conditions: p = 10 bar (145 PSI), t = 649 °C (1,200 °F).

Sealing of a centrifugal pump for the production of aromatic compounds at Shell in the Netherlands. The high drive power of 75 kW makes it necessary to apply a high efficiency NMB-22P-9R-35-ND magnet coupling. This uniquely efficient magnetic coupling drastically reduces power losses and the associated heat generation.

Operating conditions: p = 35 bar (508 PSI), t = 20 °C (68 °F), n = 990 min⁻¹.

Several metal expansion joints are employed in the ethylene cracker at Nova Chemicals in Sarnia, Ontario, Canada.

Operating conditions: p = 3.45 bar (50 PSI), t = 420 °C (788 °F).

Bayer in Leverkusen, Germany, uses several screw spindle pumps to manufacture preproducts for polyurethane production that are sealed with MAK66S3 type magnetic couplings. The process media are various polyethers with viscosities up to 3,500 mPas.

Operating conditions: p = 6 bar (87 PSI), t = 20 … 80 °C (68 ... 176 °F), n = 350 … 1,500 min⁻¹.

At the cumene alkylation plant operated by a German chemical company, a series of chemical standard pumps are sealed with Cartex type cartridge seals. The process medium is a mixture of aromatic hydrocarbons, so the TA-Luft (Technical Instructions on Air Quality Control) must be taken into account. A TS2000 type Thermosiphon system is used to supply the seals.

Liquid, high-purity ethylene is pumped in the cracker operated by the Dow Olefinverbund in Böhlen, Germany. The pump shaft is sealed by a MFLCT80S1 type triple seal. The metal bellows seal has clear benefits at the temperatures down to -100 °C (-148 °F) encountered in this environment. A TS2000 type Thermosiphon system supplies the seal.

A type DGS30 gas-lubricated mechanical seal is used to seal a compressor in BASF’s synthesis gas plant in Shanghai, China. Nitrogen-buffered Espey WD400 floating ring seals seal the bearings. The process medium is carbon dioxide.

Operating conditions: p₁ (dynam.) = 18.5 bar (268 PSI), t = 70 °C (158 °F), n = 25,750 min⁻¹.