Internal elliptical manhole is an inlet structure used for pressure vessels, storage tanks, and other equipment. Its core feature is that the elliptical cover opens inward, combining space optimization and safety sealing performance. The following provides a detailed introduction from the aspects of structural design, application scenarios, material standards, and localized supply:

1、 Structural Design and Technical Characteristics

1. Internal opening structure

The lid is opened to the inside of the container through a hinge device to avoid occupying external space.

2.Elliptical cross-section

Compared to circular manholes, elliptical designs can reduce the opening size and weaken the structural strength of containers under the same area

3. Sanitary grade design

The commonly used models in the food and pharmaceutical industries adopt mirror polishing (Ra ≤ 0.8um) and FDA certified sealing rings (silicone, EPDM, etc.), which comply with 3-A hygiene standards

2、 Application Fields and Industry Standards

• Food and BeverageCleaning and maintenance of fermentation tanks and pasteurization equipment

• pharmaceutical industryAseptic inspection and maintenance of reaction vessels and sterile filling lines.

• Chemical and EnergySafety maintenance of high-pressure reaction vessels and hydrogen storage containers

2. International and industry standards

3-A Sanitary StandardRegarding the food processing environment, specify the surface roughness of manholes, compatibility and cleanability of sealing materials

FDA and EHEDGThe pharmaceutical and high-purity industries require manhole materials to be non-toxic, corrosion-resistant, and certified by relevant hygiene standards

3、 Materials and Manufacturing Processes

main material

Made of 304/316L stainless steel (compliant with ASTM A240), some models use ASME BPE grade 316L, which has excellent corrosion resistance and is suitable for acidic and alkaline environments

sealed system

shimSilicone (temperature resistance -10 ℃~+100 ℃), fluororubber (chemical corrosion resistance), in compliance with FDA 177.2600 standard