Applicable Scenarios: For pumps conveying Class A or extremely/highly hazardous media (such as benzene, hydrogen sulfide, cyanide, high-temperature oils, etc.) or high-pressure pumps (typically ≥10MPa) with operating temperatures ≥ auto-ignition points, single-end mechanical seals or packing seals are prohibited. Leak-free structures such as double-end mechanical seals, tandem seals, or magnetic drives must be used.
Legal Basis: The Ministry of Emergency Management's 2024 "Catalogue of Outdated Hazardous Chemical Safety Production Processes, Technologies, and Equipment (Second Batch)" clearly requires relevant in-service equipment to be upgraded within 3 years; failure to do so may result in production shutdowns, fines, or even liability. Article 42 of the Environmental Protection Law requires enterprises to bear the responsibility for pollution control and compensation caused by leaks.
Technical Standards: The sealing system must comply with API 682 (centrifugal pump shaft seal) or JB/T 8059 (high-pressure reciprocating pump seal) standards. Key indicators include leakage ≤5ml/h (Class 2), a buffer monitoring system (double-end face), and pressure and temperature resistant matching media (e.g., using PTFE/metal graphite/silicon carbide friction pairs).
Environmental Additional Requirements: If the medium contains VOCs, heavy metals, or recalcitrant substances, the leaking seal must be equipped with steam recovery, a collection tank, or online leak detection. While pumps carrying clean water media such as high-pressure water jets pose no risk of chemical pollution, they still require protection against oil leakage (e.g., plunger pump lubricating oil) and must comply with the "Integrated Wastewater Discharge Standard."
Operation and Maintenance Responsibilities: Regularly perform seal leak checks (soap water/infrared leak detector), establish leak records, and replace seals for hazardous waste disposal (e.g., oil-containing graphite gaskets). Compliance obligations cannot be evaded under the pretext of "minor leakage."
