CHRYSSAFIDIS S.A. supplies
two series of grooved fittings:
The globally known fittings from Tyco/Grinnell
As well as
The more affordable fittings from RECOMB
A SYSTEM FOR CONNECTING STEEL PIPES WITH GROOVED
ENDS
Recent times have seen the widespread use of a
system for the connection of steel pipes with grooved
ends. The system includes fittings and accessories
with significant technical and economic advantages.
The grooved end system can tolerate high pressure,
vacuum, and external buffeting, while reducing the
need for external supports, expansion joints, etc.
The system is used in fire-fighting, hydration,
heating, cooling, gas, and pneumatic transfer applications.
.
ASSEMBLY
The heart of the system is
the coupling, which is made up of a two-part body, a rubber
gasket and the tightening bolts.
A. Flexible or Rigid Body
The body of the grooved couplings permits the
self-centering of the pipe. The body encloses and
retains the gasket, ensuring the system is watertight.
The ends of the coupling rest in the pipes' grooves,
preventing separation due to internal pressure.
Both flexible and rigid couplings are available.
Flexible couplings create a predefined gap between
the coupling and the pipe grooves, which permits
both angular and longitudinal movement. Conversely,
rigid couplings secure the pipes and prevent any
separation or movement. In both cases, the pipes
have to have grooves. Grooving can be done either
by forming (rolling) or by cutting away parts of
the pipe.
The couplings are fully painted and, as such,
are suited for regular use, such as that involving
atmospheric corrosion. For highly corrosive conditions,
hot dip galvanized and stainless steel couplings
are used.
The two parts of the coupling are connected by
two oval headed bolts. Their head is positioned
in the body in such a manner as to prevent the rotation
of the bolt during the tightening of the nut. Tightening
the nut only requires one wrench.
B. Gasket
The C-shaped gasket securely waterproofs the system,
under both internal pressure and internal vacuum.
The diameter of the gasket and its internal structure
create a very tight fit with the pipe, ensuring
that the connection is watertight and airtight.
Pressure from inside the pipes enters the hollow
of the gasket and compresses the lips of the gasket
on the pipe, making it even more watertight. In
pipes with vacuum, the gasket compresses as a result
of external pressure, and this also ensures that
the system is watertight. The gasket is constructed
of various elastomers, such as EPDM, BUNA-N, FLUOROELASTOMER
and silicone. The variety of materials used in the
gasket makes the Grinnell / RECOMB system suitable
for use with many types of fluids, such as water,
acids, bases, salts, petroleum, vegetable oils,
gas, hydraulic fluids, lubricants, etc.
TECHNICAL CHARACTERISTICS
The basic characteristics of the system
are as follows:
Rigid or Flexible
Both rigid and flexible couplings are available.
Flexible couplings counteract expansion resulting
from temperature changes, reducing the need for
expansion joints.
Self-stabilizing fittings
The couplings enter the peripheral grooves of
the pipe and ensure the strength of the connection.
Noise and vibration
The elastomers used in the construction of the
grooved couplings help reduce noise and absorb
vibration.
Ease of disassembly
The grooved couplings are easily disassembled
for maintenance purposes. In systems carrying
abrasive fluids, the couplings permit the rotation
of the pipes to distribute evenly the effects
of the corrosion.
Flexibility
The flexibility of grooved couplings helps compensate
for any changes in the course of a pipe. This
permits positioning of the pipes for inclined
drainage and on irregular grounds.
Angular Flexibility
The flexibility of grooved couplings also compensates
for abrupt changes in a pipes' course resulting
from landslides or seismic activity. This reduces
wear and tear on the actual pipes themselves.
ADVANTAGES
The grooved system has significant
benefits over other methods of connecting pipes, such
as those involving welding or flanges.
FEATURE
FLANGES
WELDING
GROOVED
Ability to change the course
of pipe
Compensation for expansion and
contraction of the pipes
Reusability of pipes
Reliability of pipe connection
Compensation for anomalies in
pipe ends
No welding needed
No weakness at point of connection
No risk of physical injury during
installation
Easy and quick installation
System is completely re-usable
Low total cost of installation
Can be installed by non-specialized
personnel
Flexibility of pipe connections
Absorption of vibration
The key advantages of the grooved
system are:
1. The reduction of the total cost of installation for
about 30% to 40% of the cost of using flanged connections.
2. The installation time required when using the system
can be as much as 70% less than that required when using
other systems.
Comparison of the cost of assembling
4'' pipes
ASSEMBLING WITH FLANGES
COST OVERVIEW
2 FlangesPN
16
8 bolts
M16x65 and nuts
Gasket
2 Welds
Welding
material
Assembly
Total
cost euro
Time
Cost
(18,0 euro/h)
2x4,7 euro = 9,4
euro
8x0,2 euro= 1,6
euro
1x0,7 euro = 0,7
euro
2x20 min= 40 min
40 min x 18,0 =
12,0 euro
1,5 euro
10 min
3,0 euro
28,2
ASSEMBLING WITH WELDING
COST OVERVIEW
Execution
of welding at site of connection
Welding
materials
Total
cost euro
Required time (with
preparation)
Cost (18,0 euro/h)
25 min
25 min x 18,0=
7,5 euro
1 euro
8,5
ASSEMBLING WITH GROOVED FITTINGS
COST OVERVIEW
Cost
of unskilled labor (9,0 euro/h)
Total
cost euro
1 coupling
Time needed to
make 2 grooves 2x2 min = 4 min
Time needed for
assembly 5 min
Cost of labor
9 min x 9,0 euro/h
5,05 euro
= 1,35 euro
6,4
Range of fittings
Flexible
couplings
1''-24''
Rigid couplings
1''-12''
Concentric reducers
1,25''x1''-12''x10''
Eccentric reducers
1,25''x1''-12''x10''
Butterfly valves
with grooved ends PN20
2''-8''
Caps
1''-24''
Reducing couplings
2''x1,5''-8''x6''
Grooved flanges
2''-12''
Elbow
90°
1''-24''
Elbows
45°, 22.5°, 11.25°
1''-24''
Tees
1''-24''
Crosses
1''-12''
Reducing
Tees
1,25''x1,25''x1''-24''x24''x20''
Grooved caps with BSP thread
2''-10''
Flanged Couplings
2''-12''
Clamp-T Branch coupling with grooved outlet
for pipes 3''-8''
Clamp-T Branch coupling with threaded outlet
for pipes 3''-8''
search
Application fields
contact details
System of grooved end pipe connection 
The globally known fittings from Tyco/Grinnell
