Garlock GYLON Style 3500 PTFE Gasket Sheet

Name: Garlock GYLON Style 3500 PTFE Gasket Sheet – Datasheet & Quote
Brand: Garlock
SKU: Style 3500

Silica-filled fawn PTFE sheet for strong acid service

GYLON Style 3500 is the fawn PTFE sheet filled with silica. It is the GYLON style Garlock lists for strong acids, except hydrofluoric acid, along with solvents, hydrocarbons, water, steam, chlorine and cryogenics.

Garlock’s feature list includes a tight seal, improved performance over conventional PTFE, reduced creep relaxation, excellent bolt-torque retention, a manufacturing process that limits cold flow, and branding and colour coding that reduce misapplication. The material will not support flame or bacterial growth, and the spec sheet cites ABS, FDA and USDA.

Technical specifications

Parameter	Specification
Manufacturer / style	Garlock, GYLON Style 3500
Composition	PTFE with silica
Colour	Fawn
Fluid services	Strong acids (except hydrofluoric), steam, solvents, hydrocarbons, chlorine and cryogenics
Temperature, minimum / ideal operating limit / maximum	-450 °F (-268 °C) / 400 °F (204 °C) / 500 °F (260 °C)
Pressure, minimum / ideal operating limit / maximum	Full vacuum / 750 psig (52 bar) / 1200 psig (83 bar)
P x T maximum	350,000 psig x °F (12,000 bar x °C) for 1/32 and 1/16 in; 250,000 (8,600) for 1/8 in
Specifications printed	ABS; FDA; USDA; will not support flame or bacterial growth
Compressibility, ASTM F36	7 to 12 %
Recovery, ASTM F36	40 %
Creep relaxation, ASTM F38	18 %
Tensile strength across grain	2000 psi (13.8 N/mm2)
Specific gravity / density	2.10
Design factors, ASTM F586 (m; y)	1/16 in and under: m 5.0, y 2750 psi (19.0 N/mm2); 1/8 in: m 5, y 3500 psi (24.1 N/mm2)
Gasket constants, ROTT	1/16 in: Gb 949, a 0.253, Gs 2.6; 1/8 in: Gb 1980, a 0.169, Gs 0.393
Sealing characteristics	ASTM F37B Fuel A at 1000 psi (7 N/mm2) gasket load and 9.8 psig (0.7 bar): 0.22 ml/hr; DIN 3535 nitrogen at 4640 psi (32 N/mm2) and 580 psig (40 bar): less than 0.015 cc/min
Catalogue example on garlock.com	0.094 in x 60 x 60 in sheet (2.4 x 1524 x 1524 mm), fawn, branded

Values are the typical properties printed in the Garlock spec sheet (August 2023). Garlock marks them as a general guide.

Specifying Style 3500: limits and design values

The silica filler gives a sheet that is firmer than 3504 but softer than 3510: compressibility 7 to 12 %, specific gravity 2.10 and creep relaxation 18 %. The ASME design factors are m 5.0 with y 2750 psi (19.0 N/mm2) up to 1/16 in, and m 5 with y 3500 psi (24.1 N/mm2) at 1/8 in, so allow for adequate seating stress.

The datasheet excludes hydrofluoric acid from the strong acids listed for Style 3500, while Garlock lists the graphite-filled Style 3530 for highly concentrated hydrofluoric acid. Pressure goes to 1200 psig (83 bar) with 750 psig ideal, and temperature to 500 °F with 400 °F ideal, both based on ANSI raised-face flanges at Garlock’s preferred torque. Close to the limits, ask Garlock Applications Engineering.

Related Garlock gasket sheets

Choose among the GYLON styles by filler and chemistry, as summarised here.

Garlock style	Composition	Colour	Media and use printed by Garlock
GYLON Style 3504	PTFE with aluminosilicate microspheres	Blue	Many acids, some caustics, hydrocarbons, solvents, hydrogen peroxide, refrigerants, cryogenics
GYLON Style 3510	PTFE with barium sulfate	Off-white	Strong caustics, moderate acids, chlorine, gases, steam, hydrocarbons, cryogenics
GYLON Style 3530	PTFE with graphite	Black	Monomer service, cryogenics, concentrated hydrofluoric acid, volatile hazardous air pollutants
GYLON Style 3565 ENVELON	PTFE with aluminosilicate microspheres (ENVELON)	White exterior, blue interior	Moderate acids and caustics, hydrocarbons, glass-lined equipment

Documents, ordering details and quotation

Tell us the acid, concentration and temperature when asking for Style 3500. To price the job we need the medium, pressure, temperature, flange details, available bolt load, thickness and quantity, and whether sheet or finished gaskets are wanted. The datasheet figures are typical test values, so have the final selection reviewed against the real operating conditions, and ask Garlock for a chemical compatibility opinion where the medium is unusual. Related products are in gaskets, seals and pipe fittings.

GYLON and BLUE-GARD gasket sheets

The sheets listed here come from two families. GYLON is the PTFE based range for chemical, food and pharmaceutical duties, and BLUE-GARD is the aramid fibre range for water, oils, steam and gases. Each official spec sheet shows the style, service limits, typical properties and the approvals that are printed on it.

Seven Star LLC links the manufacturer document on every product page, so buyers can verify the figures and approvals themselves before they send an inquiry.

Choosing the right style

The correct style depends on the medium and concentration, temperature, pressure, flange facing and bolt load. Send these details with your request for quotation and we compare them with the published Garlock data before we quote, referring critical duties back to the manufacturer. Sheets can be quoted as whole sheets or as gaskets cut to size.

Frequently Asked Questions