Ethylene

FlexArmor^® Overview

Ethylene Corporation's Flexarmor Flexijoint expansion bellows combine the high pressure rating of a metallic expansion joint with the high temperature and near-universal corrosion resistance of PTFE. They are designed for services where the unreinforced Flexijoint PTFE bellows is unsuitable.

Seamless, heavy walled, isostatically molded PTFE liners provide excellent resistance to permeation. This high integrity liner offers a superior alternative to the conventional PTFE spray coated or seamed liner. They are subjected to uncompromising quality control before and after lining of the bellows.

Pressure ratings for Flexarmor bellows are as high as 285 psig. The metallic outer bellows features uniform wall thickness and multiple ply construction for increased flexibility. These bellows are available in most nickel alloys including Monel, Inconel and various types of stainless steels. Available designs include: universal joints, hinged-pinned and slotted, and gimbal types. Versatile manufacturing techniques accommodate customization of Flexarmor bellows' flanging, overall length, movements and spring rates.

Flexarmors can be custom engineered for specific process requirements while maintaining high flex cycle fatigue life

FlexArmor^® Standard construction includes:

• Flanging — Class 150 carbon steel flanges with clearance holes per ANSI B16.5.
• Bellows Carcass — Fabricated from type 321 stainless steel.
• Liner — Heavy walled, isostatically molded, seamless PTFE.
• Tie Rods — Flexarmor Bellows are supplied with three(3) threaded, carbon steel tie-rods that have been set to the maximum design length to prevent over-extension of the bellows in service.

FlexArmor^® Options

Tandem Expansion Joint/Bellows

Constructed from two Flexarmor Bellows, this unit is designed for applications where extra long face to face dimensions are required to provide increased axial movement.

A custom overall length can be specified.

Universal Expansion Joint/Bellows

Constructed from two Flexarmor Flexijoint bellows connected with a PTFE lined pipe section, these units are designed for use where large lateral displacements are encountered or where minimal lateral reaction forces are desired. This is critical when mating to glass, glass lined steel and graphite nozzles. The overall length of the unit is tailored to meet lateral, axial and angular displacement and load (i.e. spring rate) constraints.

Consult Ethylene Corporation for additional information and assistance.

Hinged Expansion Joint/Bellows

Hinged expansion bellows are useful when support of an adjacent pipe spool by the expansion bellow's flanges is required. These bellows allow angular movement of the adjacent piping while restricting axial and lateral displacement. A hinged, pinned and slotted expansion joint design is frequently used where large lateral or angular movements are expected.

FlexArmor^® Engineering Data

Engineering Data
Nominal Diameter	Bellows Inside Diameter (in)	Metal Bellows Wall (in)	PTFE Liner Thickness (in)	Flare Face (in)	Flange Outside Diameter (in)	Flange Thickness (in)	Number of Holes	Hole Diameter (in)	Bolt Circle Diameter (in)	Maximum Allowable Working Pressure
1-1/2	1 13/16	.016	.090	2 7/8	5	11/16	4	5/8	3 7/8	285 psi
2	2 5/16	.018	.095	3 5/8	6	3/4	4	3/4	4 3/4
3	3 5/16	.024	.100	5	7 1/2	15/16	4	3/4	6
4	4 1/4	.024	.110	6 3/16	9	15/16	8	3/4	7 1/2	175 psi
6	6 1/16	.036	.120	8 1/2	11	1	8	7/8	9 1/2
8	8	.042	.131	10 5/8	13 1/2	1 1/8	8	7/8	11 3/4
10	10	.048	.141	12 3/4	16	1 3/16	12	1	14 1/4
12	11 15/16	.060	.152	15	19	1 1/4	12	1	17
14	13 1/8	.072	.160	16 1/4	21	1 3/8	12	1 1/8	18 3/4
16	15	.072	.175	18 1/2	23 1/2	1 7/16	16	1 1/8	21 1/4	150 psi
18	16 7/8	.072	.191	21	25	1 9/16	16	1 1/4	22 3/4
20	18 13/16	.072	.198	23	27 1/2	1 11/16	20	1 1/4	25
24	22 5/8	.072	.222	27 1/4	32	1 7/8	20	1 3/8	29 1/2	125 psi

FlexArmor^® Neutral Length and Allowable Movement

The neutral, face-to-face length and the maximum allowable axial movements for Flexarmor Flexijoints are given in Table 2 below. The numbers listed in Table 2 represent the normal overall length of bellows as shipped. The axial extension and compression are the maximum movements from the neutral position. A Flexarmor bellows can be supplied to your exact neutral length and/or movement specifications. Please consult the factory with your unique requirements.

Neutral Lengths and Allowable Axial Movements (+Extension / -Compression)
Nominal Diameter	4		5		6		7		8		9		10		11		12
1-1/2	Not Available		Not Available		5	+3/16 -5/16	5 1/2	+7/32 -3/8	6	+1/4 -7/16	6 1/2	+9/32 -1/2	7	+5/16 -9/16	7 1/2	+11/32 -5/8	8	+3/8 -11/16
2					5	+3/16 -5/16	5 1/2	+7/32 -3/8	6	+1/4 -7/16	6 1/2	+9/32 -1/2	7	+5/16 -9/16	7 1/2	+11/32 -5/8	8	+3/8 -11/16
3					5 7/8	+1/4 -7/16	6 7/16	+9/32 -17/32	7	+5/16 -5/8	7 9/16	+3/8 -22/32	8 1/8	+7/16 -13/16	8 11/16	+1/2 -29/32	9 1/4	+9/16 -1
4					6 3/8	+9/32 -1/2	7	+5/16 -19/32	7 5/8	+11/32 -11/16	8 1/4	+13/32 -25/32	8 7/8	+15/32 -7/8	9 1/2	+17/32 -31/32	10 1/8	+19/32 -1 1/16
6					7 1/4	+11/32 -5/8	8	+13/32 -3/4	8 3/4	+15/32 -7/8	9 1/2	+9/16 -1	10 1/4	+5/8 -1 1/8	11	+11/16 -1 1/4	11 3/4	+3/4 -1 3/8
8	6 1/2	+1/4 -15/32	7 5/16	+11/32 -5/8	8 1/8	+7/16 -25/32	8 15/16	+17/32 -15/16	9 3/4	+5/8 -1 3/32	10 9/16	+23/32 -1 1/4	11 3/8	+13/16 -1 13/32	12 3/16	+29/32 -1 9/16	13	+1 -1 3/4
10	7	+9/32 -1/2	7 7/8	+3/8 -21/32	8 3/4	+15/32 -13/16	9 5/8	+9/16 -31/32	10 1/2	+21/32 -1 1/8	11 3/8	+3/4 -1 5/16	12 1/4	+27/32 -1 1/2	13 1/8	+15/16 -1 11/16	14	+1 1/16 -1 7/8
12	7 3/4	+5/16 -9/16	8 3/4	+13/32 -3/4	9 3/4	+1/2 -15/16	10 3/4	+5/8 -1 1/8	11 3/4	+3/4 -1 5/16	12 3/4	+7/8 -1 1/2	13 3/4	+1 -1 11/16	Note: Flexarmor bellows cannot be subjected to simultaneous full-rated axial, lateral and angular misalignments. Consult Ethylene Corporation for specific information.
14	8 3/4	+5/16 -9/16	9 15/16	+13/32 -3/4	11 1/8	+1/2 -15/16	12 5/16	+5/8 -1 1/8	13 1/2	+3/4 -1 5/16	14 11/16	+7/8 -1 1/2	15 7/8	+1 -1 11/16
16	9 1/4	+3/8 -11/16	10 1/2	+1/2 -15/16	11 3/4	+5/8 -1 -3/16	13	+25/32 -1 7/8	14 1/4	+15/16 -1 11/16	15 1/2	+1 3/32 -1 15/16	16 3/4	+1 1/4 -2 3/16
18	9 3/4	+3/8 -11/16	11	+1/2 -15/16	12 1/4	+5/8 -1 3/16	13 1/2	+25/32 -1 7/8	14 3/4	+15/16 -1 11/16	16	+1 3/32 -1 15/16	17 1/4	+1 1/4 -2 3/16
20	10 1/2	+7/16 -3/4	11 7/8	+9/16 -1	13 1/4	+11/16 -1 1/4	14 5/8	+27/32 -1 1/2	16	+1 -1 3/4	17 3/8	+1 5/32 -2	18 3/4	+1 5/16 -2 1/4
24	11 1/4	+7/16 -3/4	12 11/16	+9/16 -1	14 1/8	+11/16 -1 1/4	15 9/16	+27/32 -1 1/2	17	+1 -1 3/4	18 7/16	+1 5/32 -2	19 7/8	+1 5/16 -2 1/4