VALVES LESSON SEVEN

1.DEFINITION A device used to regulate or control the flow of fluids ( liquid, air or gas ), in pipeings, systems and in machinery.

1.DEFINITION A device used to regulate or control the flow of fluids ( liquid, air or gas ), in pipeings, systems and in machinery. 2. VALVE OPERATING GEAR  Cam  Roller  Tapet  Push rod  Rocker arm / lever  Valve spring  Valve

3. PARTS  Valve cage - valve housing.  Valve stem / valve spindle – the rod by means of which the disk or plug is moved to open or close a valve.  Valve head / valve lid – disk part of poppet valve that gives a tight closure on the valve seat.  Valve seat – the circular metal ring on which the valve head / valve disk / valve plug of a poppet valve rests when closed.

3. PARTS  Valve cage - valve housing.  Valve stem / valve spindle – the rod by means of which the disk or plug is moved to open or close a valve.  Valve head / valve lid – disk part of poppet valve that gives a tight closure on the valve seat.  Valve seat – the circular metal ring on which the valve head / valve disk / valve plug of a poppet valve rests when closed.  Valve guide – a channel which supports the stem of a poppet valve for maintanance and alignment.

3. PARTS  Valve cage - valve housing.  Valve stem / valve spindle – the rod by means of which the disk or plug is moved to open or close a valve.  Valve head / valve lid – disk part of poppet valve that gives a tight closure on the valve seat.  Valve seat – the circular metal ring on which the valve head / valve disk / valve plug of a poppet valve rests when closed.  Valve guide – a channel which supports the stem of a poppet valve for maintanance and alignment.  Valve rorator – a device rotating the valve stem.

Adjusting valve clearance

3. PARTS  Valve cage - valve housing.  Valve stem / valve spindle – the rod by means of which the disk or plug is moved to open or close a valve.  Valve head / valve lid – disk part of poppet valve that gives a tight closure on the valve seat.  Valve seat – the circular metal ring on which the valve head / valve disk / valve plug of a poppet valve rests when closed.  Valve guide – a channel which supports the stem of a poppet valve for maintanance and alignment.  Valve rorator – a device rotating the valve stem. POPPET VALVE – is a cam-operated or spring loaded reciprocating engine mushroom – type valve used for control of admission and exhaust of working fluid. Its direction of movement is at right angle to the plane of its seat. OHV engine means overhead valve engine, i.e. an engine having valves in the head.

4. MATERIALS  Valve stem / valve spindle – of heat resistant steel  Valve seat – steel with stellite welded on it ( 65% Cobalt, 32% Chromium, 3% Tungsten )

4. MATERIALS  Valve stem / valve spindle – of heat resistant steel  Valve seat – steel with stellite welded on it ( 65% Cobalt, 32% Chromium, 3% Tungsten )  Valve cage – cast iron

4. MATERIALS  Valve stem / valve spindle – of heat resistant steel  Valve seat – steel with stellite welded on it ( 65% Cobalt, 32% Chromium, 3% Tungsten )  Valve cage – cast iron 5. STRESSES High pressure and temperature due to combustion.

4. MATERIALS  Valve stem / valve spindle – of heat resistant steel  Valve seat – steel with stellite welded on it ( 65% Cobalt, 32% Chromium, 3% Tungsten )  Valve cage – cast iron 5. STRESSES High pressure and temperature due to combustion. 6. REQUIREMENTS  Strong, sturdy construction / manufacture.  Carefully cooled

4. MATERIALS  Valve stem / valve spindle – of heat resistant steel  Valve seat – steel with stellite welded on it ( 65% Cobalt, 32% Chromium, 3% Tungsten )  Valve cage – cast iron 5. STRESSES High pressure and temperature due to combustion. 6. REQUIREMENTS  Strong, sturdy construction / manufacture.  Carefully cooled 7. COOLING Is executed by F.W. circulation, as excessive temperature may give rise to damage by cracking.

8. MATERIAL Cast or forged steel Special cast iron