National Stainless Steel Centre (NSSC), one of the largest independently owned metal processing and fabrication centres in South Africa that specialises in stainless steel has announced the launch of its newly commissioned Dished End Division, adding to the many metal processes that the company already offers. These include laser cutting, high-definition plasma cutting, water jet cutting guillotine, CNC punching, bevelling, bending, conventional and CNC plate and section rolling, CNC milling, machining and drilling, CNC tube bending, polishing and surface finish including deburring and robotic welding. Additionally the company offers pre-fabrication for structural section, pipes and other services to client requirements and project planning, including in-house quality control.
“This strategic expansion enhances our capability to supply high-quality dished ends manufactured to exact standards for the pressure vessel, tank, food, beverage, dairy, pharmaceutical, and chemical industries,” stated Managing Director Mischel Frljak.
The Faccin dishing press supplied by Talmac Machine Tools
“We are more than a service centre cutting metal to size. When we established National Stainless Steel Centre 21 years ago we knew we had to stand out from the rest. At the time many companies processing flat sheet and plate were finding that they had to offer some level of fabricating services to help them stand out among other metal processors. But we needed to be even more recognisable in a competitive and growing industry. This is one of the reasons why we chose to concentrate on stainless steel,” explained Frljak.
“But it wasn’t just about stainless steel. We figured the more metal processing processes you can offer the better it is for the client, whether it is cutting, forming, machining, joining and finishing methods to turn metal into finished components or structures. As we all know the cost of transporting today is of real significance when quoting. Allowing the client to virtually get full steel processing to their requirement from a single supplier offers clients a streamlined one-stop-shop experience. This approach simplifies the supply chain, reduces logistical headaches, and ensures consistent quality from raw material to finished component. This is what we offer as stainless steel shop,” explained Frljak.
“One of the metal processing services that we were missing from our portfolio was dishing or dished end manufacture.”
“In industry there are numerous calls for barrel or vessel type fabrications that are needed and there are hundreds of manufacturers of tanks, silos, pressure and storage vessels, rail and road tanks and other metal rolled components. Most of these companies would need to source the ends that form the end of the tank or vessel and these are known as dished ends. The dished end is usually welded to the tank or vessel body to support the pressure inside. There are various types, sizes, depending on the specifications and what type of product, liquid or solid, that will be housed in the tank or vessel.”
“Dish end manufacture is a specialised business within the fabricating world but the call for the use of dish ends is numerous. Pressure vessels are used primarily in the transport and storage industries and I can name hundreds of industries that require pressure vessels. The food and beverage, gas, petroleum, heating, chemical, cooling, water filtration and brewery industries, to name a few, all require pressure vessels in some form or shape. In fact, any industry that is using a pressure vessel or storage tank requires a convex end.”
“Dished ends are also known as end caps and as I said are welded to the main body of a pressure vessel or tank.”
“These dished ends are produced in different ways, and every method has its pros and cons. These methods include hot and cold forming, deep drawing, spinning, as well as the forming of heads in crown and petal segments.”
“Another common method is called dishing and flanging, a technique that provides manufacturers with the flexibility, high productivity, and quality of the end product required in today’s competitive market. A dishing and flanging line can form heads of any shape, be it flat, conical, standard, torispherical, semi-elliptical, or ellipsoidal. Material thicknesses range from 5mm to 60mm in the cold condition and up to 80mm in the hot condition. Diameters range from less than 1m up to more than 8m. This shows how versatile the production with a dishing and flanging line can be.”
The Faccin knuckle cold forming machine used to manufacture dished heads, supplied by Talmac Machine Tools
“Once the plate has been cut to size in a circular shape (using a circular shear, laser, plasma, or other method), the resulting dish is formed under a press that, with multiple hits distributed over the entire surface, will crown the plate. To make different types of dished ends and different diameters, a dishing press must be equipped with a set of dies shaped with different radii.”
“Because of the situation of where and what these vessels and storage tanks are used pressure vessels are design to ASME and PD design codes and storage tanks to API 650, BS 2654, and associated specifications. We therefore have to adhere to these codes as well.”
Faccin dishing press PPM-400/6
“We decided on a Faccin PPM series dishing press, which is a heavy-duty hydraulic dishing press designed for crowning metal plate ends. The PPM-400/6 has a 400-ton capacity hydraulic press configured for plates or throat capacities up to 6 000mm.”
“Faccin’s PPM series of hydraulic dishing presses are built with the exclusive HPT system utilising two solid forged tie rods (permanently preloaded) to keep the frame connected to the top rail. Thanks to the HPT system, which is able to minimise frame deformation, dished heads presses of the PPM range assure forming precision and high reliability.”
“The Faccin has been supplied and installed by Talmac Machine Tools.”
NSSC was established just over 18 years ago in Jet Park, Gauteng. In 2013 the company moved into its own building that is made up of 10 000m² for processing and another 1 000m² for office space, in Pomona Road, Kempton Park. NSSC provides a comprehensive range of services for forming of sheets, plates, tubes and pipes, available in a wide range of stainless steel grades, diameters and thicknesses.
For further details contact National Stainless Steel Centre on TEL: 011 552 8800 or visit www.nssc.co.za
