A case study of tank blanketing valves
104 tank blanketing valves for the first refinery financed with private funds on the Chinese archipelago of Zhoushan near the city of Ningbo in Zhejiang Province
This purchase order arrived at Mankenberg GmbH -the German valve manufacturer- at the end of 2018. The first stage of this newly built oil refinery comprises 104 partly very huge fuel tanks which have to be inerted with nitrogen. It was an unusual project for the German company. The refinery was built on an artificially created group of islands about 300 km air-line distance southeast of Shanghai. For this purpose, 42 hectares of artificial land were dredged. The refinery complex is operated by Zhejiang Petroleum and Chemical Co.
It took less than half a year for all 104 tank blanketing valves to be delivered. A large part of the applications were served by a pilot operated millibar control valve (Mankenberg RP 840). The pressure reducing valve consists of a main valve for large flow rates, combined with a millibar control valve as pilot. Both valves are made of deep-drawn stainless steel to be particularly corrosion resistant. This was only one of the requirements of the company ZPC; another one, for example, is the soft-seated, balanced valve plug, which ensures high valve tightness.
The RP 840 was the best solution for the conditions of the artificial archipelago. The valve is corrosion resistant and has a low dead weight due to the use of deep-drawn stainless steel components instead of heavy cast bodies, which facilitates installation on the tanks. Other special features include its high control precision and constant control in the millibar range (usually only 0.002 – 0.004 bar), as well as the durable valve elastomers.
A DM 762 pressure reducer was supplied for each of the 12 smaller tanks on the island. It also controls very low back pressures with small or medium flow rates. This valve is also made of deep-drawn materials and is very lightweight.
The tank blanketing story goes on
With this order from China, Mankenberg asked itself whether there was another way to serve the different applications in the tank blanketing segment. The in-house development department was involved in this case study. Two years later, at the end of 2020: Eureka! The Mankenberg engineers and product management found this other approach. In the research phase, they talked about new valve series, studied the tank blanketing market, wrote specifications and thought in all directions. But the solution lay in redesigning the existing Mankenberg DM 586. The valve was technically adapted in such a way that it could have served some applications of the RP 840 in 2018 even without a pilot valve.
The end of the tank blanketing story
The result of these internal R&D costs and efforts: If today’s technical and design optimizations of the Mankenberg tank blanketing valve DM 586 had already existed in 2018, approx. 40 % less acquisition costs would have been incurred on the customer side. Cost savings from which today’s tank farm operators take advantage. That is how industry works! And who knows what major order future tank farms will benefit from? Mankenberg GmbH, at any rate, will never stop optimizing itself and its portfolio.
“We have been existing since 1885, and progress has always been a guiding principle at Mankenberg GmbH.”
Axel Weidner – managing partner and great-grandson of the company’s founder.
By the way, Mankenberg GmbH is involved in many other exciting projects with its tank protection valve solutions, among others for BASF, Oiltanking, Bayer Pharma, ExxonMobile, GlaxoSmithKline, Ratiopharm, Unilever and many more.
Just ask the valve experts at Mankenberg GmbH if you wish to learn more about these tank protection systems.
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