Electric knife gate valve will lead to a new round of technological innovation The biggest impact of similar foreign products on the valve industry is the application of new materials and the adjustment of the structure of similar products and the extension of performance. This kind of influence is very big and its degree is different. The foreign development of new valve products focuses on the application of new valve materials. The electric knife-type gate valve cannot fully meet the needs of its technological development due to the existing corrosion-resistant valve materials. The output of ultra-low carbon stainless steel valves is very small, so foreign valve The industry is accelerating the development of ultra-low carbon duplex stainless steel valves. Ultra-low carbon two-way stainless steel has the ability to resist point corrosion, intergranular corrosion, and uniform corrosion under conditions of resistance to chloride ions, hydrogen sulfide, carbon dioxide, inorganic acids, and organic acids. Second, foreign valve industry is paying more and more attention to the application of nanomaterials on valves. Nanotechnology is the cutting-edge technology for the development of science and technology in the world. In the research of nanoplastic valves, nanomaterials can only reach the sub-nanometer level in the equipment manufacturing industry, and nanometer-scale processing of powders for manufacturing valves. The original plastic particles are relatively large. After a new process, they can be neatly arranged and finely powdered particles. After sintering and high-temperature die casting, the entire cavity of the valve is obtained. The plastic valve has good corrosion resistance and is very high. The strength can replace the special stainless steel valves used in petroleum, chemical industry, especially in thermal power plant desulfurization equipment and other corrosive environments. In addition, nickel-based nano powders are made by the carbonyl method, and the nickel-based nano powders are coated on the sealing surface using a laser coating technique or a supersonic coating technique, so that the sealing surface hardness can reach HRC 62-70, thereby improving the sealing of the valves. Surface wear, erosion resistance, corrosion resistance, thereby increasing the service life of pneumatic knife valve. Fourth, the application of ceramics on the valve, due to ceramics can greatly improve the corrosion resistance of the valve, the service life and sealing performance is better than carbide, ceramics used as a seal vice, such as the instrument valves used in power plants are mostly ceramic ball Sealed, with high hardness, high temperature, long life and other advantages. Fifth, the development of different uses of rubber, such as hydrogenated nitrile rubber (HNBR) on the resistance to hydrogen sulfide corrosion, can be applied to the valve sealing surface. Hydrogenated acrylonitrile-butadiene rubber (HNBR) can be applied to the valve seat of the API6A gate valve so that the gate valve has a high lifetime and is resistant to hydrogen sulfide corrosion. The impact of advanced updates of foreign products of the same kind on China's valve industry mainly manifests itself in: substitution of key valve products for China's key projects; occupation of its vast market; intensifying market competition among China's valve industry, etc. From this point of view, , The impact of foreign similar products on the domestic valve industry can not but be said to be another worrying issue! More vacuum pump information is available at China Vacuum Pump Trading Network (/).
A dumbwaiter is a small
freight elevator or lift intended to carry objects rather than people.
Dumbwaiters found within modern structures, including both commercial, public
and private buildings, are often connected between multiple floors. When
installed in restaurants, schools, kindergartens, hospitals, retirement homes
or in private homes, the lifts generally terminate in a kitchen.
The term seems to have been
popularized in the United States in the 1840s, after the model of earlier
"dumbwaiters" now known as serving trays and lazy Susans. The
mechanical dumbwaiter was invented by George W. Cannon, a New York City
inventor. Cannon first filed for the patent of a brake system (US Patent no.
260776) that could be used for a dumbwaiter on January 6, 1883. Cannon later
filed for the patent on the mechanical dumbwaiter (US Patent No. 361268) on
February 17, 1887.Cannon reportedly generated a vast amount of royalties from
the dumbwaiter patents until his death in 1897.
A simple dumbwaiter is a movable
frame in a shaft, dropped by a rope on a pulley, guided by rails; most
dumbwaiters have a shaft, cart, and capacity smaller than those of passenger
elevators, usually 45 to 450 kg (100 to 1000 lbs.) Before electric
motors were added in the 1920s, dumbwaiters were controlled manually by ropes
on pulleys.
Early 20th-century codes
sometimes required fireproof dumbwaiter walls and self-closing fireproof doors
and mention features such as buttons to control movement between floors and
locks on doors preventing them from opening unless the cart is stopped at that
floor. Dumbwaiter Lifts in London were extremely popular in the houses of the
rich and privileged. Maids would use them to deliver laundry to the laundry
room from different rooms in the house. They negated the need to carry handfuls
of dirty washing through the house, saving time and preventing injury.
A legal complaint about a
Manhattan restaurant's dumbwaiter in 1915, which also mentions that food orders
are shouted up and down the shaft, describes its operation and limitations as
follows:
[There is] ... great play between
the cart of the dumb-waiter and the guides on which it runs, with the result
that the running of the cart is accompanied by a loud noise. The rope which
operates the cart of the dumb-waiter runs in a wheel with a very shallow
groove, so that the rope is liable to and does at times slip off. ... The cart
has no shock absorbers at the top, so that when it strikes the top of the shaft
or wheel there is a loud report. ... [T]he ropes of the dumb-waiter strike such
wall at frequent intervals with a loud report. ... [T]he dumb-waiter is often
negligently operated, by running it faster than necessary, and by letting it go
down with a sudden fall.
More recent dumbwaiters can be
more sophisticated, using electric motors, automatic control systems, and
custom freight containers of other kinds of elevators. Recently constructed
book lifts in libraries and mail or other freight transports in office towers
may be larger than many dumbwaiters in public restaurants and private homes,
supporting loads as heavy as 450 kg (990lbs)
Dumbwaiter Lifts Dumbwaiter Lifts, Service Lifts, Service Lift, Dumb Waiter, Dumbwaiter Lift CEP Elevator Products ( China ) Co., Ltd. , https://www.elevatorcomponent.nl