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Technical Features

Principle and methood of assembly
Advantages of the R88 unions
Kind of fluid
Temperature
Storage conditions
Pressure
Manufacture according to standards
Materials
Cationic electropaint of steel fittings
Inspection procedure
Assembly procedure of R88
Degree of tightening
Main fields of application of the unions
Simbolic designation of the unions

 

PRINCIPLE AND METHOOD OF ASSEMBLY

The R88 unions permit the quickest junction between rigid and semirigid tubing of all diameters and materials steel, copper, aluminium or plastic as weel as the connexion between the tubings and the installations components, without threads, flanging or abnormal effort.

The R88 union set is comprised of the following:

  Nut
  Split tapered ring whit internal grooved diameter or not grooved in terms of the service pressure or customer´s requeriments, made in accordance to the tube material.
  Washer.
  Sealing "O" ring.
  Body

Features

ADVANTAGES OF THE R88 UNIONS

KIND OF FLUID

Normal union is adecuate for water and air. (Joints : NBR)
For other kind of fluids, indicate the type.

TEMPERATURE

Standard union -20ºC to 130ºC
Other temperatures, please consult.

TEMPERATURE / COMPATIBILITY
O-RING MATERAL TEMPERATURE RANGE AIR WATER PETROLEUM BRAKE FLUID MINERAL OIL BUTANE METANE NATURAL GAS
80º 150º
NBR (70) -30ºC , +120ºC
FKM (70) VITON -20ºC , +250ºC
EPDM FKM (70) -50ºC , +150ºC
SILICON VQM (70) -50ºC , +200ºC

R88 ensures the performance of its products as long as the nature of the fluid, the conditions of pressure, temperature and environment have been previously specified and notified to us.

STORAGE CONDITIONS

Due the fittings are assembled with sealing O-rings, these should be stored according to the NFT 47-507 normative

PRESSURE

D   -- Outer diameter , mm. and inches.
Pm -- Highest test pressure, bars.
Pl   -- Highest service pressure fpr liquids, bars.
Pa  -- highest service pressure for gas, bars

HYDRAULIC PRESSURE
  200 bar 100 bar 80 bar 40 bar
D     1/8   1/4   3/8     1/2   3/4   1 1 1/4   1 1/2 2
TUBO 6 8 10,2 12 13,5 16 17,2 18 20 21,3 25 26,9 30 33,7 42,4 44,5 48,3 60,3
Pm 400 360 345 330 300 260 250 240 220 210 180 175 165 140 90 75 75 60
Pl 250 240 230 230 200 175 165 160 145 140 120 118 110 92 60 50 50 40
Pa 150 120 120 115 100 86 83 80 73 70 60 55 50 46 33 25 25 20

MANUFACTURE ACCORDING TO STANDARDS

MATERIALS

CATIONIC ELECTROPAINT OF STEEL FITTINGS

INSPECTION PROCEDURE

ASSEMBLY PROCEDURE OF R88

Check outer of the tube to be connected and standard limits.
Deburr the end of the tube.
Carry out the assembly as follows:

  a) The nut
  b) The split tapered ring
  c) The trust washer
  d) The "0" rubber ring (NBR)

Introduce the tube in the coupling, approx. half of its lenght.
Thread the nut and all elements are tightened. The rubber "O" ring (4), forced into its housing by the washer (3), makes the tightness and the nut taper causes diametral contraction of the split ring against the tube. The assembly process is finished.

NOTE:

The stripping resistance of the unions depends on the degree of tightening. For instance, an union of 3/8" tightened by hand is sealed but it can be stripped off at 10 bars. Screwed up with a wrench it stands 200 bars.

DEGREE OF TIGHTENING TROQUE (daN.m)
D

PIPE

    1/8   1/4   3/8     1/2   3/4   1 1 1/4   1 1/2 2
6 8 10,2 12 13,5 16 17,2 18 20 21,3 25 26,9 30 33,7 42,4 44,5 48,3 60,3
STEEL 3,2 4 4,7 5 6 7 8 9,5 9,5 10 12,5 14 16 18 25 30 37 42
STAINLESS STEEL 3,2 4 4,7 5 6 7 8 9,5 9,5 10 12,5 14 16 18 25 30 37 42
COPPER 1,6 2 2,5 2,8 3,2 3,6 4 4,8 4,8 5 6,3 7 8 9 12,5 15 15 21

MAIN FIELDS OF APPLICATION OF THE UNIONS

Railway industrie:
R-88 type unions are approved by RENFE and rolling stock constructors to be used in brake circuits pneumatic and hydraulic devices, heating, cooling and ventilation water circuits.
Suburban railway companies have also approved the R-88 type unions for the same applications as before.

Ship industrie:
Spanish shipping and manufacturing companies use the unions for all kind of piping inside the ships as sea water circuits, fuel, oil, heating, pneumatic, etc.

Power plants:
Thermic and nuclear power plants are a wide field for the unions, as all diameters from the very small 4mm. to the biggest 1000mm. are covered by the available range of R-88 unions.

SIMBOLIC DESIGNATION OF THE UNIONS

2   MATERIALS 4   MEASURES 6  CONICAL RING 7   "O" RING
A   STEEL DT   D/TUBE BCA - SMOOTH NBR -20ºC / +130ºC
L   COPPER dt     d/TUBE BCAS - RIFLIN SPECIAL REQUEST
X   STAINLESS STEEL RM   MALE THREAD BCL - SMOOTH JNBT NBR BT -45ºC / +110ºC
3   TREATMENT RH    FEMALE THREAD BCX - SMOOTH JE EPDM -50ºC / +170ºC
C   CATIONIC ELECTROPAINT A    SMOOTH ADAPTOR SIDE BCXS - RIFLIN JV VITON -20ºC / +250ºC
B   ZINCED A3C ISO 4042 JS SILICONE -50ºC / +250ºC
G   GALVANIZED
DESIGNATION 1 2 3 4 5 + 6 7 EXAMPLES
SIMPLE UNION U 2 3 DT   + 6 7 UAC 18 +BCXS / JNBT
REDUCING UNION UR 2 3 DT dt + 6 7 URA 18 - 12 +BCAS
BULKLEAR UNION PC 2 3 DT   + 6 7 PCL 12 +BCL / JE
STOPPER B 2 3 DT   + 6 7 BX 2 +BCX / JV
PLUGGING OV 2 3 DT         OVA 18
MALE ADAPTOR UNION UM 2 3 DT RM + 6 7 UMA 1 - G 1 B +BCAS
FEMALE ADAPTOR UNION UF 2 3 DT RH + 6 7 UFX 18 -G 1/2H +BCX
EQUAL ELBOW E 2 3 DT   + 6 7 EA 28 +BCAS
EQUAL TEE T 2 3 DT   + 6 7 TAC 28 +BCXS / JNBT
EQUAL CROSS C 2 3 DT   + 6 7 CAC 28 +BCL / JNBT
REDUCER ADAPTOR AUR 2 3 A DT + 6 7 AURA 28 - 12 +BCAS
STRAIGHT STEM MALE ADAPTOR AM 2 3 A RM     7 AMX 2 - G 2 B
STRAIGHT STEM FEMALE ADAPTOR AF 2 3 A RH       AFL 18 - G 1/2 H
BULKHEAD FOR WELDING PP 2 3 DT   + 6 7 PPA 28 +BCAS
MALE ELBOW EM 2 3 DT RM + 6 7 EMAC 1 - G 1 B +BCXS
REDUCING NIPPLE RI 2 3 RM RH       RIC M-1/4 - H 1/8