Gestra PK 40NS Sample Cooler

Data Sheet 818911-00 Issue Date: 04/09
Sample Cooler
PK 40
Description For the safe operation of steam boilers the analysis of boiler water, boiler feedwater and condensate is of great
importance. Accurate and true analytical findings require correct sampling methods and properly working analytical
instruments.
A water sample can be taken from a steam boiler, a steam regenerator, a feedwater tank or a condensate receiver tank.
For example, if hot uncooled boiler water is taken from a steam boiler for analytical purposes, the risk of accidents for
operating personnel will be higher and errors in the water analysis due to flashing will occur. Some of the uncooled
boiler water flashes off as flash steam and, as a consequence, the density of the sample will appear higher and
does not represent the true salt content (TDS value) of the boiler water. The increased concentration of non-volatile
solids in the sample results in an incorrect water analysis and, consequently, excessive boiler blowdown. The GESTRA
sample cooler PK 40 is designed to safely cool down the boiler water sample to a reference temperature of 25 °C.
As a result a true sample is obtained and the TDS value, pH value and oxygen content truly corresponds to the boiler
water. The PK 40 is supplied as an assembled unit ready for installation.
All continuous blowdown valves BA(E)... from GESTRA are equipped with a sampling valve to which the sample cooler
PK 40 can be connected.
Function The pressurised boiler water, boiler feedwater and condensate flows through a high-pressure needle valve and through
the cooling coils of the sample cooler PK 40. Completely demineralised water (make-up water) flows in the opposite
direction through a ball valve and then through the housing into the cooling water discharge line of the PK 40. At maximum cooling water flowrate the high-pressure needle valve
reduces the amount of boiler water coming from the steam boiler until the reference temperature is reached and can be
read off the water sample thermometer of the PK 40. The reference temperature is in compliance with the accredited
state of the technical art. This representative boiler water sample can now be used for analysis and is drawn from the
sample outlet. The sampling and the chemical analysis of the dissolved solids must be in accordance with the pertinent rules and regulations.
Design
PK 40 (standard):
Constructed in high-alloy stainless steel 1.4571, supplied as assembled unit ready for installation and fitted with ball valve,
high-pressure needle valve and water sample thermometer.
The housing is completely welded, the cooling coils cannot be removed.
PK 40 (for laboratories):
Suitable for sampling applications where the sampling point and the analysis facilities are in separate rooms (e. g. in
test laboratories). Design as standard version but the unit is completely assembled, interconnected and mounted on
a supporting plate.
Technical Data
Efficiency 1.5 kW with water samples at 200 °C with 7 l/h sampling flowrate referered to 25°C
The cooling capacity of the sample cooler PK 40 decreases as the temperature of the cooling water increases.
Materials Housing and cooling coils: 1.4571 Needle valve:
1.4571 Ball valve:
1.4408 Surface treatment Outside: passivated and pickled (optionally: with electropolishing)
Inside: passivated and pickled Pressure/Temperature Ratings Max. service pressure for housing: 10 bar
Max. service temperature for housing: 100°C Max. service pressure for cooling coils: 40 bar
Max. service temperature for cooling coils: 260°C Mechanical connection (standard version)
Sampling inlet:
Progressive ring fitting 8 mm Sampling outlet:
Tube ∅ 8 x 1 Cooling water inlet: G ½ Cooling water outlet: Tube ¾" Thermometer:
G½ Mechanical connection (version for laboratories) Sampling IN :
progressive ring fitting 12 mm Sampling OUT :
progressive ring fitting 12 mm Cooling water IN:
G½A Cooling water OUT: G ½ A Thermometer:
G½ Weight approx. 8 kg approx. 20 kg (version for laboratories)