api 682 mechanical seal free sample

API 682 has created definitions for many of the common features and attributes of mechanical seals and systems. When new concepts are introduced or options are added to the standard, they must be captured in the definitions.

Type A is a balanced, cartridge mounted seal which utilized elastomeric secondary seals. Type B is a cartridge mounted seal which utilizes the flexible metal bellows and elastomeric secondary seals. The Type C Seal is a cartridge mounted high temperature bellows seals which utilizes flexible graphite secondary seals. Other requirements such as face materials and elastomers are tied to these definitions.

This article contains excerpts from the paper, "Advancements in mechanical sealing -- API 682 Fourth Edition" at the 2013 International Pump Users Symposium held at Houston, Texas.

The Fourth Edition of API 682 expands on these definitions slightly. Type A and B seals have historically been defined as having flexible rotating elements. This means that the springs or bellows assembly will rotate with the shaft. This was selected as the default design in the First Edition due to the high population of these designs in the refinery industry. Type C seals have historically defaulted to stationary flexible elements.

API 682 Seal. Viking’s seal chamber will accept almost any customer-specified brands and types of API 682-compliant Category 1, 2 or 3 cartridge mechanical seals, and can provide API seal plans to meet application requirements. Standard seal is a category 2 single mechanical seal. Carbon vs. silicon carbide with API Plan 13.

3mm corrosion allowance above Maximum Allowable Working Pressure (MAWP). The XPD 676 has an additional 3mm corrosion allowance built into all pressure containing components over and above our standard steel Universal Seal series pumps.

Casing drain and seal chamber vent. XPD 676 has cast-in casing drain with ANSI Class 300 RF flange and seal chamber vent to completely drain the casing before maintenance.

Mechanical seal designers face challenges when developing dual seals. Although originally aimed at the hydrocarbon processing industry, the American Petroleum Institute"s seal standard (API-682/ISO 21049) is very widely used because it lists many universally applicable requirements. Among them is the intent to optimize seal face cooling, which must also mesh with the need to provide a seal that tolerates pressure reversal and abrasive or congealing fluids. Poor seal face cooling can certainly reduce equipment reliability. The seal standard, therefore, offers users a choice of three different configurations and, as can be expected, each version has advantages and disadvantages.