What is the difference between manhole and handhole?
Publish Time: 2021-04-29 Origin: Site
What is the manhole?
A manhole or an inspection chamber is a unit constructed underground to provide access to the utilities like a sewer system, drainage system, etc. Hence, with the help of a manhole, underground utilities are inspected, modified, cleaned and maintained.
Whenever possible, we try to locate these pipes and manholes outside of the roadway, but that is often not possible because we either don't have enough property outside of the roadway to fit the pipes, or we have other things in the way that would conflict with the pipes and the manholes, such as drainage structures, power poles, etc.
And of course, when planning to lay underground power cables, drains, etc. it also makes sense to put them under bits of land that you can tear up from time to time without having to knock a private citizen’s house down to do so.
Manholes, mostly found in the streets of cities, serve as access points to various underground utilities including sewers, electricity, telephone lines, gas lines and storm drains.
When the depth of sewer exceeds 4 feet, five feet etc., then there will be a manhole.
All are meant for checking the sewer lines at the time of blockage of sewage.
Manhole cover with the frame, steel steps, sewer pipes etc., access fittings.
The Features of Manhole
The main parts of a manhole are the chamber or ring and the Vertical Circular Pipe. The vertical circular pipe is available in varying depth and sizes. These pipes are used to access the inspection joints in the system.
Manholes are mainly positioned 0.5m away from the curb lines of the road. Mostly it is constructed such that it is away from the wheel line of the traffic.
The cover of a manhole is a plug that protects the manhole from any unauthorized access. The covers used for manholes can be either rectangular, square or circular in shape. The material of cover can be precast concrete, composite material or any glass-reinforced plastic material.
The provision for access through the manhole is performed through steps. If the depth of the manhole is less than 1 m, a step ladder is constructed. If the depth of the manhole is greater than 2.5m, a regular ladder is fitted. Now modern manholes do not demand physical entry.
The Purposes of Manhole
There is a large amount of heavy particulate matter in the sewage which settles in the manhole to avoid being washed into the pipes or sewage treatment system causing blockages. Therefore, the manhole is a very important part of the drainage system.
The main purpose of a manhole is:
To perform inspection, cleaning, and removal of any obstruction present in the sewage line.
The joining of sewers, the change of direction or the alignment of sewers can be performed with the help of a manhole.
These have a perforated cover which helps the foul gases to escape. Hence it is a good means of ventilation for the underground sewage system.
Manholes help to lay the sewer line in conventional lengths.
What is the handhole?
A Handhole is a shallow metal electrical utility or pulls box (also called an access ,underground enclosures or splice box) installed within a run of conduit or ducts that allows for easy access to pull in, splice and terminate wires or cables.
A handhole is a type of manhole, buried underground just deep enough so that its lid is flush with the surface of the ground; its opening is just wide enough for the insertion of one’s hand and/or arm.
A hand hole is an open structure for a person's hand or tool to reach into the equipment for installation, maintenance or inspection. It is mainly composed of short tubes, flanges and handhole covers with handles. Commonly used hand hole nominal diameter of 150 ~ 250mm, hand hole materials are carbon steel and stainless steel. The hand hole according to the pressure situation is divided into normal pressure and pressure hand hole; according to the opening speed is divided into ordinary and fast-opening hand hole. Fast-opening hand hole is used for frequent opening occasions and is divided into normal pressure, rotary handle and very large turn cover hand hole.
Underground pull box are designed for pulling, splicing and storing cables, as well as accessing underground electricity, telephone, telecommunications, CATV or water pipes. They are an alternative to traditional concrete service boxes.
An electrical box that offers aesthetic and functional benefits, keeping electrical systems and electrical connection points out of reach. Products vary by size, load rating, availability of a bottom and other considerations.
The difference between manhole and handhole
There is an obvious difference between the manhole and handhole----Diameter.
A manhole is a hole usually in the ground that is Man could get into to do the work. However, a handhole is a hole large enough for a hand to go into it, usually to balance a man or provide a hole of size for a hand to use.
In addition, a manhole or an inspection chamber is a unit constructed underground to provide access to the utilities like a sewer system, drainage system, etc. Hence, with the help of a manhole, underground utilities are inspected, modified, cleaned and maintained. A Handhole is a shallow metal electrical utility or underground enclosures installed within a run of conduit or ducts that allows for easy access to pull in, splice and terminate wires or cables. A manhole, a vital part of the drainage system, can obstruct a large amount of heavy particulate matter in the sewage, but a handhole means an open structure for a person's hand or tool to reach into the equipment for installation, maintenance or inspection.
How to select?
Choosing the proper manhole drain cover are often a frightening task for people who don’t affect the day in and outing. Although they appear to be pretty self-descript, manhole covers are available in a spread of dimensions, sizes and materials and not choosing the right one or not replacing a damaged cover can potentially be detrimental.
The key's in understanding your application and having the ability to answer the subsequent questions:
What size do I need?
What weight loading should it be?
What sort of cover do I want?
What sort of seal should it have?
As you undergo this list the selection of canopy could also be determined for you. for instance, if you are looking for a canopy during a highway, you'll only use cast/ductile iron BS EN 124 covers rather than a steel cover.
We've put together the subsequent information where we'll cover (pun intended) the foremost common options available and offer advice on how best to answer these questions.
Jinmeng has participated in several National Standard for manhole cover and Smart City and obtained Italian ICMQ, British UKAS, ISO9000, ISO14000 and other system certifications. With a better performance than Cast Iron, Ductile Iron and RCC manhole covers. Our covers are available with load-bearing capacity ranging from 2.5 tons to 60 tons (E 600). Jinmeng specializing in providing composite manhole cover and customized composite material one-stop solution.
A Handhole is a shallow metal electrical utility or underground pull box installed within a run of conduit or ducts that allows for easy access to pull in, splice and terminate wires or cables. A handhole is a type of manhole, buried underground just deep enough so that its lid is flush with the surface of the ground; its opening is just wide enough for the insertion of one's hand and/or arm.
More solution for drainage and underground facility inspection
gully cover: Innovative SMC Composite material improvements and structure performance, Jinmeng gully cover suitable for sidewalks, drainage channel and well, underground parking area, drainage system on both sides of the road, ensuring the traffic safety, pedestrian areas and comparable parks or car parking decks. The design of large areas for leaking has a better drainage effect.
water meter box: Water meter boxes are commonly used civil infrastructure equipment and are widely used in irrigation control valves, water, sewers, electrical, recycled water, cable television, telephones, etc. The top cover of the water meter box can be opened. The back of the sidewall of the box is provided with a water inlet pipe gap through which the water inlet pipe passes.
How does one correctly measure the size
Covers are manufactured and listed by their clear opening size, which is that the size of the manhole itself, and not the size of the duvet. Because the duvet must sit securely the clear opening size is that the crucial measurement to you would like to require. it's typically measured in millimetres (mm) and may either be square (e.g. 450 x 450mm), rectangular (e.g. 450 x 600mm) or circular (e.g. the diameter - 450mm).
To measure the clear opening size for your cover you would like to require the measurements from the walls of the manhole, from one side to the opposite. If the opening is square or rectangular, you'll get to take both the width and height measurements against just the width/diameter of a circular one. you'll also get to measure the depth of the brickwork/asphalt that the duvet is going to be sitting in, referred to as the frame depth, to make sure you get the foremost accurate measurement possible.
Types Of Manhole Sealing
No seal – the duvet is typically just placed on top of its frame and that’s that. it's normally heavy-duty, forged iron or slides out covers that are unsealed.
Single seal – Most manhole covers manufactured lately are single sealed. it's essentially a tongue and groove joint which is airtight when sealed. the duvet surround is generally crammed with grease which helps form the seal.
Double seal – this is often simply a triple-tongue and groove joint, which, as you'd expect, forms a more comprehensive seal. Again this type of seal prevents air from escaping, providing the manhole isn't struggling. The double seal is usually used when foul drainage manholes are situated within buildings.