Mechanical pump seal

A mechanical pump seal assembly for sealing a rotatable pump shaft, comprising:

• a) a sleeve that is fittable to the pump shaft for rotation therewith;
• b) a stationary seal ring section surrounding the pump shaft;
• c) a rotatable seal ring section connected to said sleeve, the rotatable ring section including an upper seal member and a lower drive member, the upper seal member being made of a first material and the lower drive member being made of a second material, the upper seal member and the lower drive member being removably interlocked such that movement of the lower drive member causes movement of the upper seal member;
• d) seal faces on said seal ring sections opposed to one another, the seal face on the rotatable seal ring section being on the upper seal member;
• e) wherein each ring section has an annular groove;
• f) an O-ring that occupies each annular groove;
• g) wherein one of the O-rings engages the sleeve and surrounding the pump shaft;
• h) a cage below the drive member that rotates with said sleeve;
• and
• i) wherein the lower drive member is removably interlocked with the cage for rotation therewith.

A method of sealing a rotatable shaft mechanical seal with a seal assembly, wherein the seal assembly includes a sleeve that is fitted to a pump shaft and a stationary housing containing a chemically active fluid, comprising:

• a) providing a stationary seal ring section connected to said housing;
• b) providing a rotatable seal ring assembly connected to said sleeve, the rotatable ring assembly including an upper seal member removably interlocked with a lower drive member, the upper seal member being made of a first material and the lower drive member being made of a second material that is not said first material, the upper seal member and the lower drive member being connected such that movement of the lower drive member causes movement of the upper seal member;
• c) providing seal faces on said seal ring sections opposed to one another, the seal face on the rotatable seal ring assembly being on the upper seal member;
• d) wherein in step “c” each ring section has an annular groove;
• e) placing an O-ring in each annular groove;
• f) wherein one of the O-rings engages the sleeve and the other O-ring engages the stationary housing;
• g) placing a cage below the lower drive member and surrounding the pump shaft, said cage having a spring;
• h) rotating the lower drive member and cage together by interlocking the lower drive member and the cage;
• and
• i) biasing the stationary seal ring section and upper seal member together with the spring of step “g”.