How are control valves subject to common problems?

Control valves are subject to a number of common problems. This section is dedicated to an exploration of the more common control valve problems, and potential remedies. Control valves are mechanical devices with moving parts, and as such they are subject to friction, primarily between the valve stem and the stem packing.

What causes head gasket to leak on Mercedes C 200?

If it’s not getting hot it’s probably got a leak somewhere, and that shouldn’t be expensive to fix, but if it is getting hot it could be a leaking head gasket and fixing that could set you back quite a few bucks.

Is the Mercedes-Benz C 200 a good car?

In terms of reliability and common faults there is little difference between Mazda, Honda and Toyota. They are all good, reputable brands building cars of a good quality with few reliability issues. Choose the one that best suits your family needs. Mercedes-Benz C200 2001: What could be causing it to have coolant problems?

Do You need Timing belt change on c 200?

I’ll assume you’re talking about a C200, Kevin, which was the most popular Benz model with a 200 in its name back in those days. The good news is that, no, that engine doesn’t need a timing belt change.

What are the problems with a pneumatic actuator?

If the actuator is pneumatic, however, a more serious problem arises from the combined effects of static and dynamic friction. A simple “thought experiment” illustrates the problem.

Why does the stem of a control valve stay closed?

Instead of the stem smoothly lifting immediately as pressure exceeds the bench-set value, this valve will remain fully closed until enough extra pressure has accumulated in the actuator to generate a force large enough to overcome spring tension plus valve friction.

How is the flashing of a control valve predicted?

An important parameter predicting flashing in a control valve is the valve’s pressure recovery factor, based on a comparison of the valve’s total pressure drop from inlet to outlet versus the pressure drop from inlet to the point of minimum pressure within the valve. = Pressure recovery factor (unitless)

If the actuator is pneumatic, however, a more serious problem arises from the combined effects of static and dynamic friction. A simple “thought experiment” illustrates the problem.