mechanical seal

1

Equipment

GLAND

THROAT BUSH

FOLLOWER

PACKING

LANTERN RING

SLEEEVE

PACKING WITHSLEEVE

PACKING WITHSLEEVE

*Wear is on the sleeve

2

Horizontal Surface wear Shaft wear

Equipment

Now it essential to find a solution to avoid shaft wear, Such as finding another surface of another parts to be worn but easy and cheap to be replaced, It is the

MECHANICAL SEAL

3

Equipment

Vertical surface wear Scarifying elements

4

Rotary Elements1- Carbon ring2- Snap Ring3- “O” Rings

4- Springs5- Sleeve

Stationary Element

Tungsten Carbide ring

Or Silicon Carbide ring

Equipment

Single mechanical sealSingle mechanical seal

5

Double Mechanical seal Bellow typeDouble Mechanical seal Bellow type

BELLOWBELLOW

6

Unbalanced mechanical seal

StationaryCarbon ring

Product + Springs

Product + Springs

Contact face pressure

Contact face pressure

>PRESSURE P STRESS S

7

FACE AND SEAT AREA EQUAL 100% BALANCEFACE AND SEAT AREA EQUAL 100% BALANCE

F = P * A F = S * A

P * A = S * A

P = S

A = Contacted Surface area

S = Contacted

Surface stress

P = Product + Spring pressure

F = Acting force

S P =

100 %

AP

Carbon ring

AS

Stationary ring

8

P

S A1 ( projected area of P()product + spring

pressure(

)contacted surface stress( = A ( contacted surface

area(

120 cm2

230 cm2=

Mechanical seal has the following data: A = contacted surface area = 230 cm2

A1 = ( projected area of P) = 120 cm2Calculate the hydraulic balance Percentage

SOLUTION

= .0 52 *100 =52 %

Hydraulic balance % is less than 65 %This Mechanical is prone to leak

Hydraulic balance % is less than 65 %This Mechanical is prone to leak

9

Flushing Quenching

ATMOSPHERE

10

Circulation Circulation

CYCLONE

11

Heat control / removal

API Plan 21API Plan 21

12

Circulating Circulating liquidliquidCirculating Circulating liquidliquid

Barrier Barrier fluidfluidBarrier Barrier fluidfluid

QuenchQuenchfluidfluidQuenchQuenchfluidfluid

13

Barrier fluid Circulation

Product Circulation

Equipment

Tandem Seal

14

Tandem SealTandem Seal

Barrier fluid Circulation

Product Circulation

Equipment

Pp

Barrier fluid CirculationBarrier fluid

Circulation

PBF = 1 bar max

15

Barrier fluid TypeBarrier fluid Type

Temperature RangeTemperature Range Barrier fluidBarrier fluid

- 120 to - 90 Propanol - 120 to - 90 Propanol 0

C

- 90 to - 30 Methanol - 90 to - 30 Methanol 0

C

-30 to + 20 Kerosene or Hydraulic oil -30 to + 20 Kerosene or Hydraulic oil 0C

+20 to + 200 L.G.O. or H.G.O. +20 to + 200 L.G.O. or H.G.O. 0C