132 PDGS Mechanical Seals for Pumps Pusher Seals

(1)Features
• Gas-lubricated
• Uni-directional or bi-directional
• Elastomer-free
• Ready-to-fit cartridge unit
• Single, double, tandem seal and tandem with
intermediate labyrinth available

(2)Advantages
High quality components make this a universal seal for
a wide range of applications and the ideal solution
for standardization. The universal gas seal for centrifugal
compressors; resistant to chemicals.

Application single seal: The simplest seal is a Dry Gas
Seal in single arrangement. This seal is used in case that
due to the nature of the product gas no additional back up
seal is required. Separation seals as labyrinths, radial
clearance seals or CobaSeal are optionally available. This
version is used as an emission-free arrangement with a
corresponding flare/vent connection. Primary leakage is
then discharged with the separating gas to the primary
vent (flare). In the case of dirty gases the gas to be sealed
has to be filtered in addition and conveyed to the seal
chamber via connection "A". The resulting gas flow from
the sealing compartment prevents any dirty/wet gas gas
entering the seal.

(3)Operating range (see note on page 1)
Shaft diameter: Ds1 = 29 ... 435 mm (1.14" ... 17.13")
Pressure: p = 0 ... 450 bar (0 ... 6,525 PSI)
Temperature: t = -170 °C ... +230 °C (-274 °F ... +446 °F)
Sliding velocity: vg = 0.6 ... 200 m/s (2 ... 656 ft/s)

(4)Materials
Seal face: Silicon carbide (Q1) with DLC coating
Seat: Silicon carbide (Q1) with DLC coating
Secondary seals: Polymer rings
Metal parts: 1.4006 and other stainless steels.

(5)Standards and approvals
• NACE

(6)Item          Description
1                Seal face, stationary
2                Seat, rotating
3                Thrust ring
4                Spring
5                Shaft sleeve and seat retainer
6                Intermediate sleeve
7, 8            Housing (adapted in size to the installation space)
9                Carbon ring type separation seal
10              Labyrinth
11              Intermediate labyrinth

A                Product flushing
B                Flare
C                Buffer gas
D                Separating gas
S                 Vent

(7)Note
• Available with EagleBurgman DiamondFaces

(8)Recommended applications
• Oil and gas industry
• Refining technology
• Petrochemical industry
• Hydrocarbon gas
• Ammonia
• Nitrogen
• Refrigerants
• Air
• Centrifugal compressors
• Turbo expanders
• Blowers

Main components of the dynamic secondary seal of the PDGS
 are made of the extremely rigid material tungsten carbide
 which allows an optimum control of the extrusion clearance
 over the full range of operation. The specific design of the
 polymer cup seals ensures minimum sliding forces combined
 with wear-free operation

(9)Product variants
PDGS Tandem seal
Application: Where small product leakages of process
gas are admissible, e.g. on gas pipeline compressors.
Seal on the atmosphere side acting as a safety seal. The
tandem arrangement provides a particularly high degree
of operational safety. The seal on the product side and
the seal on the atmosphere side are able to absorb the
complete pressure differential. Under normal operating
conditions the full pressure is reduced only by the seal
on the product side. The space between the seal on the
product side and the seal on the atmosphere side is
cleared by a connection "B" to the flare. The pressure
differential to be sealed by the seal on the atmosphere
side equals the flare pressure, so the leakage to the
atmosphere side or to the vent is very low. If the main
seal fails, the second seal acts as a safety seal.

PDGS Tandem seal with intermediate labyrinth
Application: Where product leakages to the atmosphere
as well as buffer gas leakages to the product are
inadmissible, e.g. on H2, ethylene or propylene
compressors. With this version the product pressure to
be sealed is reduced via the seal on the product side.
The entire process gas leakage is discharged via
connection "B" to the flare. The seal on the atmosphere
side is pressurized with buffer gas (nitrogen) via
connection "C". The pressure of the buffer gas ensures
that a current flows via the labyrinth to the primary vent
outlet.

PDGS Dual seal
Application: Where product leakages to the atmosphere
are inadmissible and tandem arrangements are not
suitable because of too small product gas pressures.
Buffer gas leakages into the product must be admissible
(buffer pressure p3 > p1). This seal is used when a
neutral buffer gas of suitable pressure is available.
Typical applications are to be found mainly in the
chemical industry, e.g. on HC gas compressors. A
buffer gas, e.g. nitrogen, is fed between the seals via
connection "C" at a higher pressure than the product
pressure. One part of the buffer gas leakage escapes to
the atmosphere side and the other part to the product.

Dimensions in mm

We have large stock, so our delivery  is very fast.
For example,if products are standarded, the delivery time is one week.
Our company and factory addrss: Ningbo City, Zhejiang  Province,China.
Our city has a large port and an airport, so its transportation is very convenient.

Question1: What are the prices of your products?
  Answer: For each model, the unit price is listed on the website, but what is displayed on the website is only the average market price. For specific models, you can contact us for further consultation and negotiation.

  Question 2: Are you a factory or a trade company?
  Answer: We are a factory with top sales for the trade service.
Question 3: What is the minimum order quantity for each order?
  Answer: For products of regular models, the minimum order quantity is at least five. We welcome you to test the quality of our products and services through placing trial orders. Looking forward to the long-term cooperation with you.

  Question4: What is your company's service tenet?
  Answer: Quality first, service upmost. We promises that if there is any problem with the quality of the product, or if the product is damaged during the transportation, our company will be responsible for compensation, regardless of the ordder turnover value.

  Question5: Can I try to get a SAMPLE before the order?
  Answer: Sure. Our company will provide you with samples for free, but you will have to pay for the international delivery (freight collect payment).