Wenzhou Zhongding Machinery produces various types of stainless steel elliptical manholes, pressure-free quick-opening stainless steel manholes, pressure quick-opening stainless steel manholes, stainless steel chemical manholes, square stainless steel manholes, stainless steel lifting lug manholes, as well as all kinds of non-standard stainless steel manholes, large-size stainless steel manholes, and customizable non-standard stainless steel manholes.

Wenzhou Duofeng Stainless Steel is located in the Wenzhou Economic and Technological Development Zone. For many years, Duofeng has adhered to the philosophy of "customer service and quality first," diligently providing reliable stainless steel products to a wide range of clients, earning their unanimous praise. Our main products include stainless steel manholes, pressure quick-opening manholes, elliptical manholes, flanged manholes, rectangular manholes, chemical industry manholes, tanker manholes, and all specifications of manholes according to HG/T 21515-21535-2014. In addition, we offer stainless steel elbows, tees, reducers, stainless steel reducers, U-shaped tees, 45-degree reducing tees, straight-through tees, quick-release tees, elbow tees, stainless steel four-way tees, extended elbows, flanged reducers, short flanged pipes, stainless steel distributors, water distributors, elbows, traps, and inspection ports for fluid pipeline accessories. The main materials available are stainless steel 304 and 316, and we offer a full range of specifications, including customization. Clients can provide drawings or samples for the production of non-standard stainless steel products. Prices are competitive, and we welcome both new and old customers to call for inquiries!

Elliptical manhole

Product Specifications: 450*350

Category: Sanitary Manhole

Standard of Execution: Standard Handbook for Atmospheric Manhole National Standard.

Product Features: Can be freely rotated 360 degrees after the outer cover is opened.

Product Advantages: 1. Easy to open.

2. Smooth rotation for easy operation.

3. Stylish and innovative with a distinctive look.

5. Excellent sealing performance.

The elliptical manhole is named due to its elliptical shape of the manhole ring and cover. The elliptical manhole is a safety emergency venting device installed on the tank roof, commonly used with fire extinguishers and mechanical breathing valves. It can prevent accidents caused by sudden overpressure or vacuum inside the tank due to unexpected reasons, and also serves as a fire-retardant barrier. It is a safety device for protecting tanks, particularly suitable for arch roof atmospheric tanks sealed with nitrogen. It features pressure-regulated exhaust and intake, flexible opening and closing, fire-retardant, compact structure, good sealing performance, and safety.

　　Product Installation and Usage Instructions:

Elliptical manholes are available in pre-formed sizes, typically with diameters of 350-450mm or 450-550mm. The center of the manhole is usually 750mm from the floor, facilitating access for personnel during installation, cleaning, and maintenance of oil tanks and ventilation systems. Non-metallic oil tanks have manholes on the tank roof, while metallic oil tanks have them on the bottom flange. Most are circular holes with a diameter of 500-600mm, centered 750mm from the base plate, used for tank cleaning or maintenance personnel and also known as a hatch. Inspection and cleaning of oil tanks utilize manholes for lighting and ventilation. Vertical oil tanks have capacities of 5000m³ or less, equipped with 1-2 manholes; above 5000m³, two manholes are installed. The installation of manholes should be no more than 90° from the in/out oil pipelines. If only one manhole is provided, it should be placed opposite the light hole on the tank roof; if two manholes are installed, one should be opposite the light hole, and the other at least 90° away from the first.

The manhole should be located near the right side of the oil pipeline entry and exit, and it should be positioned as close as possible to the sealed door of the tank room for personnel to enter and exit, as well as for maintenance of the oil tank and ventilation connections.

Product Styles: 1. Sandblasting.

2. Interior and exterior mirror surfaces.

3. Inside: glossy; Outside: mirror finish.

4. Matte finish both inside and out.

Connection Method: Welded Installation.

Product Customization: Available for non-standard customization of various stainless steel manholes.

Product Application: The stainless steel elliptical inner-opening manhole is primarily used on container equipment in the food, brewing, and beverage engineering industries.

　　Ellipse Manhole

Product Description: Stainless Steel Elliptical Atmospheric Open Manhole (commonly referred to as Atmospheric Elliptical Open Manhole) is named due to its elliptical manhole rim and cover. The Stainless Steel Elliptical Manhole is a safety emergency venting device installed on the top of storage tanks, often used in conjunction with fire extinguishers and mechanical breathing valves. It not only prevents accidents caused by sudden overpressure or vacuum inside the tank due to unexpected reasons, but also serves as a fire-resistant barrier, ensuring the safety of the storage tank, particularly suitable for arch-shaped atmospheric tanks sealed with nitrogen. It boasts features such as pressure-regulated exhaust, pressure-regulated intake, flexible opening and closing, fire-resistant safety, compact structure, excellent sealing performance, and reliability.

Product Material Requirement: Stainless steel elliptical manholes are generally made from steel plates of 304 or 316L grade as raw materials.

Product Categories: Stainless Steel Elliptical Manholes include Stainless Steel Atmospheric Elliptical Outside-Opening Manholes, Stainless Steel Elliptical Pressure Outside-Opening Manholes (3-6 kgf/cm² pressure), Stainless Steel Elliptical Inside-Opening Manholes, and Customized Non-Standard Elliptical Manholes.

Product Installation and Usage Instructions

Manholes are available in ready-made products, with diameters typically ranging from 350-450mm to 450-550mm. The center of the manhole is generally 750mm from the floor, facilitating staff entry and exit for tank installation, cleaning, and maintenance, as well as ventilation.

Non-metallic oil tanks have manholes located on the top of the tank, while metallic oil tanks have manholes on the lower ring plate of the tank wall. Most are circular holes with a diameter of 600mm, with the center 750mm from the bottom plate. These are used for cleaning or maintenance personnel to enter and exit the oil tank and are also known as access doors. During maintenance and cleaning, the manholes are used for lighting and ventilation. The capacity of vertical oil tanks is 5000m³ or less; in such cases, 1 to 2 manholes are provided, while for tanks over 5000m³, two manholes are installed. The installation of the manholes should be no more than 90° from the oil pipelines. If only one manhole is provided, it should be placed opposite the light hole on the tank top; when two manholes are installed, one should be opposite the light hole, and the other should be at least 90° from the single manhole.

The manhole should be located near the right side of the oil pipeline entrance and exit, and it should be positioned as close as possible to the sealed door of the tank room for easy access by personnel, maintenance of the oil tank, and ventilation piping.

　　Wenzhou ZhongdingManufacture various types of stainless steel manholes, sanitation-grade manholes, elliptical manholes, elliptical inward-opening manholes, elliptical outward-opening manholes, stainless steel quick-opening manholes, stainless steel pressure quick-opening manholes, stainless steel rectangular manholes, and stainless steel chemical manholes, etc. With 20 years of experience in manhole production, our products offer great value and reasonable prices. Multi-Flo welcomes your selection.