[Q&A Question 164] 2017.06.13
Thread Content
This post was last edited by 955559 on 2017-7-21 at 23:11. [Q&A Question 164] June 13, 2017: What faults can occur in the piston of a reciprocating compressor? The reference answers will be visible after replying; points will be awarded for identifying the key points. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) Friction is generated as the piston slides along the surface of the cylinder. When friction becomes extremely high due to some fault, not only are the cylinder walls worn out, but the piston rings also get damaged or broken. In some cases, this can cause the piston to get stuck inside the cylinder; however, this phenomenon is very rare. Excessive clearance can also cause the piston to move back and forth and up and down, and in severe cases, it may lead to damage to both the piston and the cylinder. Scoring criteria: 2 Wealth points for incorrect responses; *incomplete* answers earn 3–8 points. 10 Wealth points are given for correct answers accompanied by detailed explanations; responses that are correct but lack sufficient details earn 15–20 Wealth points. Please score according to these criteria. Note: If there are editing records after answering, only those who participated will be given points. For continuous malicious spamming, 2 points will be deducted each time, with no upper limit. Pure numbers, pure emojis, or random letters unrelated to the answer are all considered malicious spamming; points will start to be deducted after three warnings. 2017 Q&A Summary Thread (updates starting now) http://bbs.hcbbs.com/thread-1657793-1-1.html 2017 Daily Question Summary Thread (updates starting now) http://bbs.hcbbs.com/thread-1657794-1-1.html 2016 Q&A Summary Thread (updates completed) http://bbs.hcbbs.com/thread-1597792-1-1.html
Wear and damage of the piston ring support ring, as well as cylinder scoring
Oil-free lubrication sealing components such as piston guide rings, piston rings, and packings wear out too quickly. (1) There are many impurities in the medium. The presence of ash, tar, moisture, and other substances in the working medium that enter the cylinder will accelerate the wear of the sealing elements, the cylinder itself, and the piston rod. Especially when the medium contains both sand and liquid, it exacerbates the wear of the piston rings and guide rings. (2) The cylinder surface roughness is damaged, causing adhesion and peeling between surfaces. (3) The clearance at the piston ring openings is too small, or the clearance between the guide ring and the cylinder is too small. (4) The excessive elasticity of the filler tension spring increases the friction and wear between the sealing ring, the locking ring, and the piston rod; it also raises the operating temperature of the piston rod. (5) Poor material quality, low wear resistance.
1. Severe wear or out-of-tolerance conditions of the cylinders, pistons, and piston rings lead to increased gaps, higher leakage rates, and an impact on the exhaust volume. During normal grinding, it is necessary to replace wear parts such as piston rings in a timely manner. If it is due to incorrect installation or inappropriate clearance, corrections should be made in accordance with the drawings. 2. Leaks caused by a poor-sealing stuffing box reduce the gas volume. The primary reason is that the stuffing box itself was not manufactured to the required standards ； Secondly, it may be due to poor alignment between the piston rod and the stuffing box during installation, which leads to wear and scratches and thus air leakage ； Lubricating oil is generally added at the stuffing box, where it serves to lubricate, seal, and cool.
Faulty intake and exhaust valves, worn packing
Piston erosion, piston ring wear,
Certain components fail, such as the piston rod coming loose from the piston nut or the piston thread becoming loose. Abnormal noises can be produced by things such as collisions caused by too small a gap between the piston and the cylinder head. All of these require staff to make judgments and then take appropriate actions.
1. Low inhalation pressure； 2. The exhaust pressure is too low ； 3. Valve failure ； 4. Piston ring failure ； 5. Packing gland failure.
Friction is generated as the piston slides along the surface of the cylinder. When friction becomes extremely high due to some fault, not only are the cylinder walls worn out, but the piston rings also get damaged or broken. In some cases, this can cause the piston to get stuck inside the cylinder; however, this phenomenon is very rare. Excessive clearance can also cause the piston to move back and forth and up and down, and in severe cases, it may lead to damage to both the piston and the cylinder.