A ball valve is a form of quarter-turn valve which uses a hollow, perforated and pivoting ball to control flow through it. It is open when the ball's hole is in line with the flow and closed when it is pivoted 90-degrees by the valve handle.The handle lies flat in alignment with the flow when open, and is perpendicular to it when closed, making for easy visual confirmation of the valve's status.
injap bola tahan lama, prestasi yang baik selepas banyak kitaran, dan dipercayai, menutup dengan selamat walaupun selepas tempoh yang lama tidak digunakan. Kualiti ini membuat mereka sangat memuaskan pematian dan kawalan aplikasi, di mana mereka sering lebih suka pintu pagar dan injap dunia, tetapi mereka tidak mempunyai kawalan halus mereka dalam aplikasi pendikit.
The ball valve's ease of operation, repair, and versatility lend it to extensive industrial use, supporting pressures up to 1,000 bar (100 MPa; 15,000 psi) and temperatures up to 752 °F (400 °C), depending on design and materials used. Sizes typically range from 0.2 to 48 inches (5.1 to 1,219.2 mm). Valve bodies are made of metal, plastic, or metal with a ceramic; floating balls are often chrome plated for durability. One disadvantage of a ball valve is that they trap water in the center cavity while in the closed position. In the event of a freeze, the sides can crack due to expansion of ice forming. Some means of insulation or heat tape in this situation will usually prevent damage. Another option for cold climates is the "freeze tolerant ball valve". This style of ball valve incorporates a freeze plug in the side so in the event of a freeze up, the freeze plug ruptures (acts as a sacrificial disk), thus making for an easy repair. Now instead of replacing the whole valve, just screw in a new freeze plug.
FUNGSI DARI VALVES ADALAH:
Berhenti dan memulakan aliran
Mengurangkan atau meningkatkan aliran
Mengawal arah aliran
Mengawal selia aliran atau proses tekanan
Melegakan sistem paip tekanan tertentu
Klasifikasi Valves
Berikut adalah sebahagian daripada klasifikasi injap biasa digunakan, berasaskan kepada pergerakan mekanikal:
Linear Motion Valves. The valves in which the closure member, as in gate, globe, diaphragm, pinch, and lift Check Valves, moves in a straight line to allow, stop, or throttle the flow.
Rotary Motion injap. Apabila ahli injap penutupan bergerak di sepanjang jalan yang sudut atau bulat, seperti dalam rama-rama, bola, plug, eccentric- dan Swing periksa injap, injap yang dipanggil injap gerakan berputar.
Quarter Turn Valves. Some rotary motion valves require approximately a quarter turn, 0 through 90°, motion of the stem to go to fully open from a fully closed position or vice versa.
Pengelasan VALVES BERDASARKAN MOTION
Jenis injap | linear Motion | Motion Rotary | suku pusingan |
Pintu gerbang | YES | NO | NO |
Globe | YES | NO | NO |
plug | NO | YES | YES |
bola | NO | YES | YES |
Rama-rama | NO | YES | YES |
Swing Semak | NO | YES | NO |
diafragma | YES | NO | NO |
picit | YES | NO | NO |
keselamatan | YES | NO | NO |
relief | YES | NO | NO |
Jenis injap | linear Motion | Motion Rotary | suku pusingan |
Kelas Penilaian
penilaian tekanan-suhu injap yang ditetapkan oleh nombor kelas. ASME B16.34, Valves-Flange, Threaded, dan Kimpalan End adalah salah satu standard injap paling banyak digunakan. Ia mentakrifkan tiga jenis kelas: standard, khas, dan terhad. ASME B16.34 meliputi kelas 150, 300, 400, 600, 900, 1500, 2500, dan 4500 injap.
Oil cahaya, lukisan hitam