Principal schemes of mechanical seals operation capability support systems

Principal schemes of single mechanical seals operation capability support systems

Р1 - pump suction pressure
Р2 - pressure in the oil seal chamber of the pump
Р2 > Р1, P2 > Рair

API 682: Plan 21	API 682: Plan 23	API 682: Plan 32
Schematic diagram of the system, which ensures efficiency of single seal with “protective” fluid, supplied from outside	Schematic diagram of the system, which ensures efficiency of single seal with fluid supply from the pump head into the seal chamber	Schematic diagram of the system, ensuring efficiency of single seal with impeller, which creates fluid circulation through the seal chamber in autonomous circuit

Pos.	Description
1	Control valve
2	Cooler (used when temperature of medium more then 150…200°С)
3	Mechanical seal UT type
4	Chamber of the pump
5	Pump
6	Impeller

Principal schemes of single mechanical seals with cooling unit operation capability support systems

Schematic diagram of the system, which ensures efficiency of seal with a built-in cooling unit and cooling fluid supply via sealing

Schematic diagram of the system, which ensures efficiency of single seal with a built-in cooling unit and cooling fluid supply via pump casing

Pos.	Description
3	Mechanical seal UT type
4	Chamber of the pump
5	Pump
Т	Output temperature measurement

Principal schemes of double mechanical seals operation capability support systems

For condensate pumps, where dry operation of face seals is possible, guaranteed buffer fluid supply may be done according to the scheme below
Рbuffer = Рpump + (0,1…0,3) Mpa
Тbuffer <= 75 °С, Gbuffer >= 0,2 m3/hour
Fluid supply from the pump head and industrial pipe-line

Поз.	Описание
1	Регулирующий вентиль
2	Торцовое уплотнение типа «УТД»
3	Дроссель
4	Обратный клапан
Р	Измерение давления
Т	Измерение температуры
G	Измерение расхода

For mechanical seals of pumps groupe

To maintain seals of a set of pumps, which operate similarly and are located closely to each other, it is possible to use the system, defined below.
Рbuffer = Рpump+(0,1…0,3) MPa
Р > Р1 – with gas supply
Р < Р1 – at gas depressurization

Поз.	Описание
1	Трубопровод охлаждающей жидкости
2	Трубопровод затворной жидкости
3	Трубопровод газа (азот, воздух и пр.)
Р	Измерение давления
Н	Измерение уровня

Principal schemes of mechanical seals UTD, UTDKh, UTT, UTTKh type operation capability support systems

API 682: Plan 54

API 682: Plan 53A

It is not required to create overpressure in the SBTU reservoir after its filling.
If pressure in pump seal chamber is less than design pressure of the reservoir (4MPa), it is not required to install a safety valve at reservoir pipes.
Face seals of “Tandem” type may be used either with a cooling unit at temperatures of pump working medium up to 400 °С, or at temperatures of working medium up to 150 °С without it.
Тcooling = 5...30 °С
Gcooling = 0,2…1,5 m3/hour
Schematic diagram of the system, which ensures efficiency of “Tandem” type seal with the SBTU reservoir

The system functions at pressure of buffer fluid (pressure in the reservoir) constantly kept within the limits:
Рbuffer = Рpump + (0,1…0,3) MPa
Gcooling = 0,2…1,5 m3/hour
If the temperature of pump working medium is 150°С, seals are used without a cooling unit, if the temperature of pumped medium is 150...400 °С - then a cooling unit is used.
Schematic diagram of the system, which ensures efficiency of double seals with the SBTU reservoir

При температурах рабочей среды насоса до 150°С применяются уплотнения без холодильника, при температурах перекачиваемой среды 150...400 °С - с холодильником.

Поз.	Описание	Поз.	Описание
1	Редуктор газовый	6	Дроссель
2	Бачок под давлением	7	Регулирующий вентиль
3	Система охлаждения бачка	Р	Измерение давления
4	Торцовое уплотнение	Т	Измерение температуры
5	Холодильник уплотнения	Н	Измерение уровня

Principal scheme of double and tandem mechanical seals operation capability support system

Р1 ~ Рpump;
Р3 > Р4 > Рpump;
Р4 > Р5 > Р1;
Rezerve pump start work if Р2 = Рpump + 0,2 MPa

Р1 ~ Рair;
Р4 << Рpump;
Р3 > Р4 > Р5;
Р3 ~ 0,6...1,0 MPa;
Р4 <= 0,1 MPa.

Поз.	Описание	Поз.	Описание
1	Емкость с запасом затворной жидкости	9	Редуктор газовый
2	Основной и резервный насосы	Н	Измерение уровня
3	Теплообменник	Р1	Давление в емкости
4	Напорный трубопровод	Р2	Давление в напоре насосов
5	Сливной трубопровод	Р3	Давление в напорном коллекторе
6	Байпасный трубопровод	Р4	Давление в уплотнении
7	Трубопровод подвода затворной жидкости	Р5	Давление в сливном коллекторе
8	Трубопровод отвода затворной жидкости	Рнас	Давление в сальниковой камере насоса