Boiler Accessories Stainless Steel Manhole Corrosion-Resistant 300 * 400 Atmospheric Pressure Quick Opening Manhole Oval Handhole Cover

Product Introduction

Manhole is an oval or circular opening opened on the boiler shell or manifold for personnel to enter the interior of the boiler for maintenance, cleaning, inspection, or upkeep. It is one of the important safety accessories of the boiler, ensuring that operators can safely enter and exit the enclosed space.

Product parameters

Company Profile

Shandong Jiaguang International is a high-tech enterprise with 30 years of experience in boiler component manufacturing. It has always adhered to the integrated development of R&D, production, sales and technical services. The company has a modern intelligent production base and a professional engineering team of more than 100 people, forming four core product portfolios: high temperature resistant grate system (including active, passive, scale type, reciprocating type), intelligent chain transmission components (including chain rods, scraper conveyor components and sinking scraper chains), precision gas cap devices (boiler gas caps and grates), special pipe solutions (boiler tubes, square tubes and pressure gears), forming a complete boiler component ecosystem.

The company is well-known throughout the country for its excellent product quality and maintains strategic partnerships with the top 15 industrial boiler manufacturers in China, including Harbin Boiler Plant, Dongfang Electric Group, Shanghai Boiler Plant, Jinan Boiler Group, Hangzhou Boiler Group, etc. The company has passed ISO9001 international quality management system certification, CE, SGS certification, and has formed a global service network covering eight major industries such as power generation, thermal energy, papermaking, and chemical industry. The products have been successfully exported to more than 30 countries and regions in Southeast Asia, Central Asia, Oceania, Africa, etc.

As a pioneer in technological innovation in the industry, Shandong Jiaguang International continues to provide full life cycle solutions for global industrial boilers, power plant boilers, and civil heating systems. By continuously improving its R&D capabilities and service system, the company is steadily moving towards becoming a global boiler parts technology benchmark and professional solution provider, and is committed to creating outstanding value for global customers by improving service experience.

Product Certification

Product packaging 
1. Principles of Packaging Design
Protection Shock proof and buffering: precision accessories (such as instruments and valves) need to be filled with foam, bubble film, pearl cotton, etc. to avoid damage caused by transportation shock.
Moisture and rust prevention: Metal components (such as pipelines and flanges) need to be coated with rust prevention oil and packaged with moisture-proof film or vacuum. Desiccant should be added during sea transportation.
Anti pressure and anti drop: Heavy accessories (such as burners and drums) are reinforced with wooden boxes or steel frames, indicating the load-bearing direction and stacking layer limits.

2. Standardization and identification
Comply with international transportation standards (such as ISO, ISTA), indicate weight, size, lifting point, "fragile", "moisture-proof", "upward" and other markings.
Dangerous accessories (such as fuel injectors) must be labeled with UN certification and comply with the International Maritime Dangerous Goods Code (IMDG).

3. Container division strategy
Small items (bolts, washers) should be packaged in a uniform size box to avoid loose parts; Large items (heat exchangers) are individually customized in wooden boxes with supporting frames inside.

Product transportation
Transportation mode selection
1. Shipping by sea
Suitable for bulk accessories such as steel plates and large pipelines, pay attention to container size (20GP/40HQ) and load balance.Sea freight requires anti salt spray treatment, with moisture-proof agents placed inside the container and sealed.

2. Land transportation
Heavy accessories (over 3 tons) require flatbed trucks or low chassis vehicles, and routes should be planned in advance to avoid height/weight restrictions.Cross border transportation inspection of various countries' requirements for wooden packaging (such as ISPM15 fumigation certificate).

3. Air freight
Urgent small items (electronic controllers) should be prioritized for air transportation, and the weight of each item should be controlled (usually<100kg) to reduce packaging weight and save costs.

FAQ:

Frequently Asked Questions about Boiler Manholes (Q&A)

Q1： What is the main function of a manhole?

A1： Manhole is a maintenance channel on the boiler, used for personnel to enter the internal space of the drum, header, etc. for cleaning, inspection, maintenance or testing, ensuring the safe operation of the boiler.

Q2： What are the standard sizes for manholes?

A2：

-Circular manhole: commonly DN400 (diameter 400mm), DN450 (diameter 450mm)

-Oval shaped manhole: 380 × 280mm (minimum size), 420 × 320mm (looser)

(According to standards: GB/T 16508, ASME, etc.)

Q3： How to deal with manhole seal leakage?

A3：

1. Replace the sealing gasket: Use high-temperature and high-pressure resistant gaskets (such as graphite wrapped gaskets, metal toothed gaskets).

2. Check the flange surface: Ensure no deformation or corrosion, and if necessary, perform grinding and repair.

3. Tighten bolts evenly: Tighten them in diagonal order to avoid leakage caused by bias.

Q4： How to choose the material of manhole flange?

A4：

-Low pressure boiler: Q235B、Q245R

-High pressure/high temperature boiler: Q345R、16MnDR、 Stainless steel (304/316)

(Need to match the material of the boiler body)

Q5： What are the precautions when installing manholes?

A5：

1. Alignment installation: Ensure that the manhole cover is completely aligned with the flange to avoid misalignment.

2. Sealing inspection: After installation, an air tightness test (such as soap water testing) is required.

3. Bolt anti loosening: It is recommended to use anti loosening gaskets or thread locking agents in high temperature environments.

For more detailed technical consultation, please feel free to contact our engineering team at any time!