Dismantling Joint for Sea Water Transportation Project

● Destination United Kingdom

● Dismantling Joint Type: Rigid type/Thrust Type according to EN545 with EN1092-2 flanges

● Temperature From: -54℃ to 85℃

● Size: DN500 PN10,DN800 PN10,DN1400 PN10,DN1800 PN16

SPECIFICATION

● Material

Body: Ductile iron body EN GJS500-7

Gasket: EPDM

Tie Rods: Stainless Steel Grade SS316

Surface: inside lined with Ebonite SCRWF ,thickness is 3mm

Outside painted with corrosion-resistant paint no less than 250um

Project Solution

Step 1

Once our R&D team received the customer’s order, we immediately designed the corresponding processing drawings according to the thickness of the inner liner.

Drawing Details

Step 2

Because the lining process requires the casting surface must be smooth and flat, in order to ensure that the lining does not bubble. Therefore, our quality control department has strictly inspected the dimension and surface of the castings after machining in accordance with the lining process requirements to ensure that there is no problem specially for Ebonite lining.

Step 3

Lining the surface in contact with seawater, because the lining thickness required by the customer is 3mm, and the lining thickness of each layer is 2mm according to our vulcanization craft, so according to the requirements of the technical department, we lined 2 layers of Ebonite, and the thickness is between 3.3mm-3.7mm which meets the customer’s tolerance requirements.

Step 4

After lining the rubber, we brush the anti-corrosion paint on the surface without lining the rubber, the thickness of the anti-corrosion paint layer is required to be not less than 250um, but if we brush at once, it is easy to appear uneven thickness, the surface is not smooth phenomenon. So we brush it in three times, each time brush a thin layer, wait for the 1st layer to dry thoroughly and then brush the second layer,and continue for third layer after the 2nd layer is dry, so as to ensure the thickness of the surface is uniform, smooth and beautiful.

Step 5

Assemble gasket and tie rods, ensure the internal Ebonite rubber shouldn’t be impact by hard objects.Because Ebonite is hard rubber,it is easily damaged by strong impact.

Step 6

After the assembling is completed, the bolt protection cap should be assembled on both ends of the bolt, in order to protect the thread of the bolt from damage. This is very important! Because the bolt thread damage, will cause the dismantling joint fail.

Note Because the vulcanisation requires high temperature 300-320 degrees, so we need to line the rubber firstly, and then brush the anti corrosion paint , to prevent the high temperature from destroying the outside paint layer . Please note that since both vulcanisation and FBE coating require high temperature, it is not possible to do both types of coating on the same part at the same time.

Dismantling Joint For Sea Water

Compared to drinking water, seawater has the following characteristics

HIGH SALINITY

Seawater has a salinity of about 3.5%, meaning there are about 35 grams of dissolved salt per liter of seawater, whereas the salinity of drinking water is extremely low, typically less than 0.05%. So for a dismantling joint that transports seawater, we want to make sure that the coating on the surface can withstand the corrosive seawater.

For a dismantling joint that transports seawater, we have three options:

01. Inside lined with harder Rubber Ebonite SCRWF, Outside painted with corrosion-resistant paint

Ebonite, also known as hard rubber or vulcanite, is a type of material made by vulcanizing natural rubber for an extended period.
Here are some key characteristics and uses of Ebonite:

CHARACTERISTICS

● Hardness

Ebonite is much harder than regular rubber, resembling the hardness of plastics.

● Color

It is typically black or dark brown, although it can be produced in other colors.

● Density

Denser than normal rubber due to the high sulfur content (typically 25-80% by weight).

● Electrical Insulation

Ebonite is an excellent electrical insulator.

● Durability

It is resistant to water, acids, and other chemicals, which makes it very durable.

Ebonite is prized for its ability to be machined to fine tolerances and for its durability in harsh environments.

02. Inside lined with soft rubber EPDM, Outside painted with corrosion-resistant paint

EPDM stands for Ethylene Propylene Diene Monomer, which is a type of synthetic rubber. It is known for its excellent weather, ozone, and heat resistance, making it widely used in various industrial and commercial applications. Here are the key characteristics and uses of EPDM:

CHARACTERISTICS

● Hardness

EPDM has excellent resistance to UV radiation, ozone, and extreme weather conditions, making it ideal for outdoor applications.

● Temperature Range

It can withstand a wide range of temperatures, from -40°C to 150°C (-40°F to 302°F), maintaining its properties over time.

● Elasticity

EPDM is highly elastic, even at low temperatures, which helps in maintaining a good seal in applications like gaskets and roofing membranes.

● Chemical Resistance

It is resistant to many chemicals, including acids, alkalis, and oxygenated solvents.

● Water and Steam Resistance

EPDM has good resistance to water and steam, making it suitable for use in water and steam handling applications.

● Durability

It is highly durable and can last for many years without significant degradation.

FOR RUBBER LINING, SHOULD WE CHOOSE EBONITE OR EPDM?

01. Ebonite must be lined for the parts that require mechanical processing

02. Ebonite should be used for the parts that have high corrosivity

03. If the dismantling joint is to be used outdoors and the rubber must have some weather resistance, then EPDM rubber should be used

04. If the dismantling joint has to take the pipe vibration itself, EPDM rubber should be used. I don’t recommend hard rubber Ebonite because hard rubber Ebonite is brittle and can crack.