Technical characteristics
1. Material and structure
The Metal gasket HZB253-640-03-24 adopts a metal winding structure made of stainless steel or high-carbon steel, combined with a graphite or flexible sealing layer, with high strength and elastic compensation capabilities, and is suitable for the flange interface of the pump body end cover.
2. Temperature and pressure resistance
The design temperature range is -50℃ to 600℃, which can adapt to the high-temperature steam environment of the boiler feed system and the temperature fluctuations caused by frequent start-stop. The multi-layer winding structure realizes the adaptive sealing surface through plastic deformation to avoid sealing failure caused by thermal expansion differences.
3. Precision machining technology
Using CNC machine tools for precision stamping, the surface finish Ra≤0.8μm ensures uniform contact with the pump body end cover and reduces local stress concentration. Edge chamfering can prevent scratches on the sealing surface during installation.
Application
- Boiler feed pump seal: used for the end cover flange seal of the HZB253-640 type booster pump drive end and non-drive end to prevent the feed water medium from leaking into the bearing chamber.
- Steam turbine auxiliary system: used as the main seal in the flange connection of equipment such as steam booster pump and circulating water pump, compatible with multi-phase media such as oil, water, and steam.
- Maintenance and replacement scenario: synchronously updated when the pump body is overhauled or the sleeve (such as FA1D56-01-06) and mechanical seal are replaced to ensure the integrity of the system seal.
Installation and maintenance points
1. Pre-installation inspection: clean the flange sealing surface and confirm that there are no scratches, corrosion or residues. Use a feeler gauge to check the gap between the gasket and the flange, and the local deviation is required to be ≤0.05mm.
2. Torque control: Tighten the bolts in a cross-symmetrical sequence, and increase the torque to the design value (usually 120-150N·m) in three steps to avoid plastic deformation of the gasket caused by overtightening on one side.
3. Operation monitoring: Combined with the 6-month maintenance cycle of the front pump, check whether the compression marks of the gasket are uniform. If there are local blackening, crushing or medium penetration marks, it needs to be replaced immediately.
4. Environmental protection: Avoid acid and alkali substances from contacting the outer edge of the gasket. Apply anti-rust grease during storage and place it in a dry environment to prevent edge oxidation and reduce sealing efficiency.
Failure mode and response
- Creep relaxation: Long-term high-temperature operation may cause creep of the metal layer. It is necessary to regularly tighten the bolts or upgrade to a reinforced gasket with an inner ring.
- Medium corrosion: If the medium contains corrosive ions such as Cl⁻, it is recommended to use Hastelloy gaskets or add anti-corrosion coatings.
Metal gasket HZB253-640-03-24 Details
