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Premium API 682 Plan 53B Seal Support System manufactured by Dandong Runhe Seal Co., Ltd. Equipped with a bladder accumulator for complete gas and barrier fluid separation, this system delivers stable pressure, zero atmospheric leakage, and extended mechanical seal service life. Suitable for high-temperature and high-pressure process pumps in petroleum, chemical, and pharmaceutical industries. Standard and customized sealing system solutions are available for harsh industrial working conditions.

What is API Plan 21?

API Plan 21 is a cooled recirculation flush plan defined by API 682-. It is specifically engineered for high-temperature process services where the hot fluid cannot sustain stable seal operation without supplementary cooling.

How Does API Plan 21 Work?

The system draws process fluid from the pump discharge, routes it through a restriction orifice for flow limitation, and then through an API 682 Plan 21 heat exchanger-. This reduces the fluid temperature before delivering the cooled flush fluid into the mechanical seal chamber.

Why Choose API Plan 21?

As a cooled derivative of Plan 11, its primary duty is cooling the flush fluid and stabilizing the mechanical seal end faces-. This function:

Suppresses process fluid vaporization

Reduces coking formation at elevated temperatures

Maintains intact lubricating liquid film between mating seal faces

These are necessary conditions to achieve low-leakage, long-term reliable seal service.

Custom Solutions from Dandong Runhe Seal Co.,Ltd.

We provide custom seal support system solutions- with properly sized Plan 21 heat exchangers for various high-temperature pumping services. As a professional mechanical seal manufacturer, we can design the right system for your specific needs.

The Dry Mechanical Seals Market is gaining strong momentum as industries prioritize emission-free, lubricant-free sealing solutions for pumps, compressors, and agitators handling hazardous or expensive fluids. The Global Dry Mechanical Seals Market has become the technology of choice in oil & gas, petrochemical, pharmaceutical, and food processing where zero leakage and minimal maintenance are non-negotiable.

The Dry Mechanical Seals market was valued at USD 3,223 Million in 2024 and is projected to grow to USD 4,639 Million by 2031, with a compound annual growth rate (CAGR) of 5.5% from 2025 to 2030. Growth is driven by tightening fugitive emission regulations (EPA, TA-Luft), rising adoption of API 682 4th Edition Type C dry gas seals in high-pressure applications, and increasing replacement of wet seals in aging plants. John Crane, EagleBurgmann, AESSEAL, and Flowserve continue to lead through advanced diamond-faced technology and modular cartridge designs.