Basics and Type Of Ring Type Joint (RTJ) Gasket

Basics and Type Of Ring Type Joint (RTJ) Gasket

What is Ring-type Joint (RTJ) Gasket?

The Ring-type Joint (RTJ) gasket may be a solid ring forged into the machined groove of AN RTJ flange. The ring sort joint gaskets ar either octangular or oval in cross-sectional.

RTJ gaskets ar typically used high pressure and high-temperature applications. it’s wide utilized in plant, petrochemical and oil field drilling industries.

The Ring sort joints square measure manufactured as per ASME B16.20. they’re dimensionally appropriate to be used with flanges manufactured as per standards ASME B 16.5, ASME B16.47, and API 6A.

Sealing Principle of type sort Joint gasket

The axial compressive load (due to bolt tightening) acts on the Ring sort joint(RTJ) gasket inflicting them to deform and flow into irregularities of flange grooves. because of this, metal-to-metal contact is created between gasket and flange that creates a seal.

The ring sort joints have a superb tightness and tolerance to temperature and pressure changes. whereas putting in a ring sort joint gasket terribly shut attention should run to their bolting up for uniform load working on the seal. Also, confirm the RTJ gasket and groove faces should be freed from imperfections and trash.

Type of Ring sort Joints gasket

There square measure 3 kinds of RTJ gasket. They are

1. R Type
2. RX Type
3. BX Type

R Type

This is the essential sort of RTJ gasket and widely utilized in petrochemical industries. they’re classified as 2 varieties base on the cross-sectional. They are

• Oval
• Octagonal

The original style of the R sort gasket is Oval. The octangular RTJ may be a modification to the oval style and provides higher sealing. R sort rings ar used for the flange rating from category a hundred and fifty to 2500. The surface end of the gasket shall not be rougher than 63µ inches.

The octangular sort is extremely used once to check with oval sort owing to high sealing potency.

RX Type

RX sort gaskets area unit match into constant groove sizes of R sort gaskets for exchangeability. The RX sort gasket is wider than the R sort seal. thence the projection face-to-face separation is going to be higher compared with the R sort seal.

RX sort gaskets area unit commonly mere up to category 5000 flanges. The surface end of the seal shall not be rougher than 63µ inches. The asymmetric cross-sectional makes the gasket self-energizing.

This type of gasket is widely used for applying wherever more practical sealing needed and additionally resist vibrations, shock loadings, etc.,

BX Type

BX sort gaskets square measure only appropriate for API half dozen BX sort flanges. These gaskets square measure used for the category rating of 2000 to 20000 psi.

The BX sort gasket includes a pressure passage hole for pressure equalization on every sealing face sides. The surface end of the gasket shall not be rougher than 32µ inches.

Type BX gaskets don’t seem to be interchangeable with R or RX gaskets. The groove on a flange that accommodates a BX gasket is dimensionally totally different to it for R and RX gaskets

The pitch diameter of the ring is slightly bigger than the pitch diameter of the flange groove. This preloads the flange and creates a pressure energized seal. it’s notably necessary to see the flange face-to-face separation that should be uniform around the entire circumference of the flange.

Identification of RTJ gasket

The outer surface of every RTJ gasket shall carry the manufacturer’s name or identification trademark. The gasket variety prefixed by the letters R, RX, or BX followed by the gasket material identification. Materials shall be known as shown in Table.

Type: 

Whether or not R, RX or BX. If R, state whether or not octangular or oval. the kind of ring to be used is going to be per the piping specification.

Ring Number: for instance, R11 can match a 1/2 in. NB with the category rating of 300-600 RTJ flang

Material: a variety of materials is obtainable. supported the sealing fluid property the RTJ gasket material is going to be selected. Refer below the table for the fabric grade. for instance, identification code D is for Soft Iron.

Standard: 

Either ANSI B16.20 or API 6A. These 2 standards square measure equivalent and interchangeable.

Advantages

• Ring sort Joints used for sealing air mass up to twenty,000 psi.
• RTJ Gaskets will be made from a spread of material to suit the method application and flange grade.
• RTJ’s area unit a particularly reliable and sturdy sealing.

Disadvantages

• The ring sort gaskets square measure unfit for utilization because of the plastic flow of the ring joint within the flange faces to making the seal.
• The cost of this gasket is incredibly overpriced compared to alternative gaskets.
• Skill labors are needed for correct installation.