We reserve the right to modify the characteristics of the equipment supplied without notice or as part of the continued development of our products.
6
Please Note
The Geminox range of products are designed to be used in installations where the complete system is
supplied by Geminox therefore when used in conjunction with other products some slight alterations to
the Electrical installation may have to be made.
Important Notice
When the system installed is “Unvented” controlling the Zone valve by way of the cylinder and
overheat thermostats, follow the steps on page 4, in this instance the zone valve is called the “Safety
shut off zone valve”, the valve is supplied with the Unvented Kit and must be installed.
The safety shut off zone valve is an important safety device of the unvented EBS tank and must
be installed. Fit the valve to the return connection of the tank connection, No. 4. The valve is
to be controlled via terminal L2 of the immersion plug or if no immersion is fitted, terminal T1
of the tank top cable plug. Please find in attached photos and fig. 11 how to connect the
“Safety shut off zone valve”.
Safety Discharge Pipe from Tundish
See Table 2 below for sizing details of safety discharge pipe from our tundish.
Table 2
Sizing of copper discharge pipe D2 for common temperature relief valve outlet sizes
Valve Outlet Size
Minimum
Size
of
Discharge Pipe
D1
Minimum Size of
Discharge Pipe
D2 from tundish
Maximum resistant
allowed, expressed as a
length of straight pipe
(ie. no elbows or bends)
Resistance created
by each elbow or
bend
G ½
15mm
22mm
28mm
35mm
Up to 9m
Up to 18m
Up to 27m
0.8m
1.0m
1.4m
G ¾
22mm
28mm
35mm
42mm
Up to 9m
Up to 18m
Up to 27m
1.0
1.4m
1.7m
Worked Example :
The example below is for a G ½ temperature relief valve with a discharge pipe (D2) having 4 no.
elbows and length of 7m from the tundish to the point of discharge.
From Table 2
Maximum resistance allowed for a straight length or 22mm copper discharge pipe (D2) from a G ½
temperature relief valve is 9.0m.
Subtract the resistance for 4 no. 22mm elbows at 0.8m each = 3.2m
Therefore, the maximum permitted length equates to : 5.8m
5.8m is less than the actual length of 7m, therefore calculate the next largest size.
Maximum resistance allowed for a straight length of 28mm pipe (D2) from a G ½ temperature relief
valve equates to 18m
Subtract the resistance for 4 no. 28mm elbows at 1.0m each = 4m
Therefore the maximum permitted length equates to : 14m
As the actual length is 7m, a 28mm (D2) copper pipe will be satisfactory.
