VALQUATIGHT GASKET

Spiral Wound Gaskets use Non-Asbestos　inorganic paper, VALQUAFOIL™ (expanded graphite) and　VALFLON™ (PTFE) tape as filler materials, and exhibit good　elasticity by means of a V-shaped hoop.

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VALQUA No.
7591
Product name
WHITETIGHT (with outer ring)

Features1
Spiral wound gasket using chemical-resisting VALFLON tape as filler material, these Spiral Wound Gaskets have precedence over other filler materials in sealing corrosive fluids and airtightness, thus are suited as gas in general and vacuum seals.
Features2
An outer ring is attached. The circumferance of the outer ring of the gasket inscribes the bolt of the flange, making gasket centering easy. This ring is also useful as a guide for adjusting the amount of reinforcement and tightening of the gasket. For use with a raised face flange, No. 7596 (with inner and outer rings) is recommended, as deformation of the inner diameter of the gasket is possible.
Features3
Please use a product with inner and outer rings if the pressure rating of the flange is Class 900 (JIS 63K) or greater, or if the nominal diameter of the flange is 650A (26B) or greater.
Features4
Together with excellent corrosion resistance and proper selection of hoop materials, they can be applied to almost all fields of applications.
Features5
Excellent airtightness greatly improves sealing performance against gas in general and vacuum.

Applicable fluids
Water, Sea water, Hot water, Steam,Crude oil, Alcohol, Animal & vegetable oil, Heat transfer oil,General solvent, Weak acid, Weak alkali,Strong oxidizing acid, strong alkali,Air, Nitrogen gas, Inert gas,Exhaust gas,Inflammable gas,Poisonous,Oxygen,Extremely low temperature liquids,
Inappropriate fluid
Application
In particular best suited as gaskets for seals for corrosive fluids and oxygen which can not be handled by other types of spiral wound gaskets, as well as for gas in general and vacuum seals.

■ Dimensions

Standard Flange

For JIS pipe flanges＝10K、16K、20K、30K、40K、63K For JPI and ANSI pipe flanges＝Classes 150, 300, 400, 600, 900, 1500, 2500 Gaskets complying with other standards such as ASME and MSS are also available. ▼ For non-st

Non-Standard Flange

Gasket thickness（mm） Manufacturing ranges
3.2(T) 10〜1500
4.5(V) 10〜3000
6.4(W) 300〜3400

Products with a gasket thickness of 6.4 mm can be fabricated with the outer diameter of the outer ring of up to 3,500.

The sign "( )" shows thickness classifications.

Round type gaskets are available.

■ Design data

Basic design With outer ring With inner ring With inner/outer ring
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Filler material：　VALFLON tape

Type note：　No. 7591 may cause deformation on the inner diameter side depending on service conditions. Please use the product with an inner and outer ring whenever possible.
Please do not use PTFE, as it is affected by molten alkaline metals, high-temperature hydrofluoic acid, chlorine trifluoride, and other materials.

■ Available ranges

Temperature（℃） Pressure（MPa）
-260〜300 20.0

1. Temperature and pressure show individual service limits.
2. The above temperature ranges vary depending on the material used for the hoops and the inner & outer rings.

■ Design criteria

Gasket factor”m” Minimum design
seating stress"y"
（N/mm2）		 Recommended
tightening stress
（MPa）Liquid		 Recommended
tightening stress
（MPa）Gas
3.0 68.9 30.0 35.0

The recommended tightening stress are the pressures required under normal conditions, and correspond to the projected area of the gasket, where fluid pressure is not taken into consideration.

Separate consultation is required, where flange deformation is anticipated for large diameter gaskets.

■ The fluid-wise available ranges

The fluid-wise available ranges

■ Upon placing order


■ FAQ

Q. Is it possible to manufacture the spiral wound gasket in sizes other than the standard size?

A. Yes, it is possible for both the gasket main unit and inner & outer rings as long as you specify the size. However, please contact us because there is a range in which manufacturing is possible such as for the width.

Q. I want to control the width of the opening in the flange such as with a sheet gasket. How should I do this?

A. Control with width of the opening in the flange is prone to cause a margin of error and an accurate tightening stress cannot be obtained. It is effective for uneven tightening, so please use it in conjunction with control of tightening torque.

Q. Please tell me about the difference in the gasket dimensions between flanges of the JPI and ASME/ANSI standards.

A. JPI basically quotes from ASME/ANSI, so there are cases in which the dimensions differ slightly due to rounding error during the millimeter conversion of the original number. We understand that, in actual use, the function of the gasket is fulfilled to an equivalent degree by both dimensions.

Q. Why does leakage occur during stop or re-operation even though there are no problems during plant operation?

A. Expansion and contraction of the flange, bolt, pipe and the like will occur due to temperature changes. As a result, a tendency of reduced tightening force in the gasket main unit is often observed when the temperature decreases (including low temperature at the time of initial re-operation), and leakage occurs due to relaxation. We therefore generally recommend a retightening of the gasket before re-operation after the first heat addition.

Q. Is retightening effective when leakage occurs?

A. Yes, it is effective. We ask that retightening during leakage be performed after relieving internal pressure. However, there are also points to keep in mind for each product, such as the possibility of damage as a result of temperature-induced hardening in the case of a compressed non-asbestos fiber sheet.

Q. I am not sure which gasket to select, so could you select it for me?

A. If you contact us together with your operating conditions, we will recommend an appropriate product based on our technician's selection.

■ VALQUA HAND BOOK TECHNICAL DATA

▶ 1．1．2  Semi-metallic gaskets and metal gaskets （１）Spiral wound gasket
▶ (b)　Achievements of spiral wound gasket (size and ratings)
▶ (c)　Selection guide
▶ (d)　Design materials
▶ (e)　Characteristics
▶ (f)　Precautions for handling

■ VALQUA HAND BOOK DIMENSIONAL DATA

▶ 1.1.3 Size for Semi-metallic gaskets and metal gaskets
▶ （３） Spiral Wound Gasket to JPI raised face flange （table 1.1.17）
▶ (4)Spiral Wound Gasket to JPI raised face flange for large‐bored steel pipe
▶ （７） Spiral Wound Gasket to ASME raised face flange （table 1.1.21）
▶ （８） Spiral Wound Gasket to ASME raised face flange for large‐bored steel pipe　（table 1.1.22）
▶ （10）Spiral Wound Gasket to TAYLOR FORGE、LADISH, JPI raised face flange for large‐bored steel pipe（table 1.1.24）
▶ （11） Spiral Wound Gasket to BS 1560 raised face flange（table 1.1.25）
▶ （12）Spiral Wound Gasket to BS 4504 raised face flange（table 1.1.26）

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