How to Maintain The Valve Set of Cummins Diesel Generator Set?

The main damages of the valve assembly parts of Cummins diesel generator sets include valve wear, valve seat ablation, valve and seat fracture, valve spring fracture, deformation or insufficient elasticity. When the Cummins diesel generator set is damaged, how to repair it? In this article, Starlight Power Generation Equipment will answer for you.

1. Valve overhaul

(1) After cleaning the valve, check whether the head of the valve is damaged. If the valve head is found to be warped or cracked. When the pits or have been worn so thin that they can no longer be reground, they should be replaced.

(2) Measure the thickness of the outer diameter of the valve head. The minimum size of 6BT diesel engine should be 2.67mm. The thickness at the outer diameter of the valve head of the KTTA diesel engine: the minimum exhaust valve is 3.05mm; the minimum intake valve is 2.16mm.

(3) Check and measure the outer diameter of the valve stem. If the rod is damaged or the limit value of the small path between the outer diameters (6BT engine valve rod is less than 11.405mm, KTTA diesel engine valve rod outer diameter is less than 12.535mm), it should be scrapped.

(4) Check whether the groove of the valve lever lock plate is worn. The valve snap ring should fit tightly with the groove. If the groove is worn and the snap ring is loose, it should be reported to the wastegate Longgang diesel generator set.

(5) If there is penetration during the valve seat sealing test, it can be ground to seal it. The ground valve cone should form an accurate 30° angle with the valve horizontal plane.

(6) If the valve is cracked or damaged, it cannot be repaired.

2. Overhaul of valve seat

(1) Check the valve seat ring:

A) Hit the cylinder head near the valve seat with a wooden hammer or rubber hammer. Check whether the valve seat ring is loose. If the valve seat ring fits loosely and bounces, replace the seat ring.

B) Check the width of the seat surface. For 6BT diesel engines, the minimum seat width is 1.59mm and the maximum is 3.18mm. For KTTA diesel engines, the minimum seat width of the intake valve is 3.05mm and the maximum is 3.56mm; the minimum seat width of the exhaust valve is 1.52mm and the maximum is 2.54mm.

If the width of the valve seat surface is not within the specified width range, some surface metal can be removed from its inner or outer diameter to reduce the width of the seat surface. If the specified seat width cannot be obtained by grinding, the valve seat must be replaced.

(2) Replace the valve seat ring:

A) Use special tools to disassemble the scrapped valve seat, or use a chisel to crack the seat and take it out. After removing the seat ring, use a special tool to repair the valve seat ring hole, and check the cracks that extend into the valve seat hole. If the crack has extended to the bottom of the seat hole, the cylinder head must be replaced.

B) If there are small cracks, they can be removed by machining. The seat ring hole can be enlarged to the repair size. The inner diameter and depth of the cylinder head valve seat hole can be measured.

The above six points are the methods and procedures of how to maintain and operate the valve sets of Cummins diesel generator sets compiled by Starlight Power Generation Equipment for your reference. If you have more knowledge about diesel generator technology, welcome to visit Starlight website or send email to us sales@dieselgeneratortech.com.