Application range and selection of ceramic ball valves
- Sep 10, 2018
- Hits: 70
China is a country with an energy structure dominated by coal. Air pollution is a soot-type pollution. Dust, sulfur dioxide (SO2) and nitrogen oxides (NOX) are the main pollutants in China's atmosphere....
Valve welding inspection
- Sep 10, 2018
- Hits: 126
Valve welding inspection generally consists of following two parts: 1. Document review: 1.1 WPS(WELDING PROCEDURE SPECIFICATION), PQR, welder qualification WPQ; 1.2 Whether supplied WPS covers key variables...
The travel of Dervos in Qinghai Province
- Sep 05, 2018
- Hits: 55
Last week, Dervos organized a travel to Qinghai province, a famous place for its natural scenery and flocks of sheep and cattle. The first stop of this journey was Ta'er Temple...
The differences between a double and a triple offset butterfly valve
- Sep 03, 2018
- Hits: 161
Butterfly valves are like ball valves however have a few focal points. They are small and when activated pneumatically, they open and close rapidly. The plate is lighter than a ball, and the valve requires...
The way of medium flow for globe valves
- Sep 03, 2018
- Hits: 19
A globe valve is designed to allow medium flow under the seat, with the aim of making the flow resistance small and saving effort when opening the valve. At the same time, when the valve is closed, the...
Connection of valves
- Aug 24, 2018
- Hits: 61
Usually valves have 7 types of connection, they are as bellow: 1. Flange connection: Flange connections are the most common form of connection between valves and piping or equipment. It refers to the...
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Introduction of six types of flange gaskets
- Aug 24, 2018
- Hits: 40
Flange gaskets are used for pipe flange connection, they are seals between two flanges. Medium, pressure and temperature directly influence the selection of flange gaskets. 1.Graphite gasket This is a...
The first 140MPa domestic cage throttle valve was successfully applied in Tarim
- Aug 10, 2018
- Hits: 54
A made-in-China 140MPa cage throttle valve was applied in Well Keshan 134 Tarim successfully. And it has been working well. The throttle valves used at the wellhead of the Keshan gas field are mostly...
How to identify refurbished valves
- Aug 10, 2018
- Hits: 182
Nowadays, the valve market is complicated, and unscrupulous traders are making huge profits by refurbishing used valves as new ones, which brings great safety hazards to the installation project. Therefore,...
The Fifth Day of DERVOS 10th ANNIVERSARY
- Jul 17, 2018
- Hits: 75
On June 28, our team came to the food stall called Oriental dragon palace spicy crayfish to have a gluttonous feast. HOT TALKS IN THAT NIGHT! And our delicious crawfish~ They had a fantasic evening...