1.What is the primary pressure boundary of a valve?
2.How does it serve and why?
3.How does it receive inlet and outlet piping?
4.What is the most economical shape to resist fluid pressure when a valve is open?
5.The basic form of a valve body is spherical, isn`t it?
6.What is a common method for reducing the overall size and cost of a valve?
7.What does the choke used on wells consist of?
8.Why are steel gaskets installed between the choke shoulder and flanges?
9.What is necessary to do in order to remove the choke?
10. Where can adjustable chokes be applied?
EXERCISE 6 Decide whether the statements are true or false. Correct them if necessary.
1.Nominal size and nominal pressure are key characteristics of gate valves.
2.Compared to globe valves gate valves have significantly better integrity.
3.Compared to a gate valve a control valve is much easier to repair.
4.Choke is a variation of needle valve and is used to control well fluid flow.
5.Check valve is used to check volume of pumped fluid.
6.Plug valve can be used both to stop and control fluid flow.
7.Most quick-union connections are designed for work with products containing hydrogen sulfide and are made of materials resistant to aggressive environment.
8.A specific feature of ball valve design is that its body is made in the form of a ball.
9.In rising stem gate valves the stem can rotate and move up and down, and in nonrising stem gate valves the stem cannot rotate.
10. Gate valves maintain straight flow with insignificant pressure drop.
EXERCISE 7 Connect the terms with their definitions.
| 1. Adjustable choke | 1. small pieces such as pipes, nipples or elbows that are used in a pipe system for connecting pipes |
| 2. nipple | 2. a valve for very accurate fluid flow control |
| 3. safety valves | 3. pipe pieces which are threaded on one end and have a wing union on the other end |
| 4. swing check valve | 4. a short pipe that has either threads or welds on both ends |
| 5. elbow | 5. a pipeline valve in which the gate is opened by direct fluid flow and is closed by reverse flow |
| 6. ball valve | 6. a choke diameter of which can be adjusted |
| 7. fittings | 7. a short bent pipe-joint with outside thread on both ends |
| 8. needle valve | 8. devices installed on a pipeline to close and open fluid flow |
| 9. quick-union connections | 9. a plug valve with the plug in the form of a ball with a through hole |
| 10. stop valves | 10. devices installed on a pipeline to release excessive pressure in a pipeline |
EXERCISE 8 Translate the sentences from English into Russian.
1.The function of safety valves is to relieve excessive pressure in a pipeline by releasing excessive volume of fluid.
2.Materials for valve seat, disk and stem include brass, bronze, malleable iron, steel or alloys or other materials depending upon working temperature and operational conditions.
3.Choke is a variation of needle valve and is used to control well fluid flow, for example, mixture of oil, gas and water produced from a well.
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4.Stopping element of swing check valve revolves on its horizontal axis, located above the center of the valve seat.
5.Nipple can have various length and thread on its ends with similar or different step.
6.Pipe elbow is used in cases when in order to lay a pipeline a straight line must be turned towards the set target.
7. Quick-union connections are used to perform well operations, associated with application of mobile equipment during well workover.
8. Working fluid passes through the check valve and lifts the plug, which can come down under its own weight when stream direction changes.
9. Gate valve consists of a handwheel and a disk controlled with a screw-shaped stem, which moves up and down at right angle to fluid flow.
10. A wedge can be solid, flexible and split.
