F-D/F-S type Liquid Seal Detonation Arrester -Operating manual-
1. The purpose of the F-D/F-S type liquid seal detonation arrester
The F-D/F-S type liquid seal detonation arrester is a protection system, whose task is to prevent the spreading of the flame, deflagration (explosion) and/or detonation arising in the pipe, towards the protected tank or equipment at the place of installation (MSZ EN 12874:2001 regulations concerning liquid seal detonation arresters). The place of installation is such a pipeline, in which only liquids are delivered, which may form a explosive vapour/(gas) - air mixture belonging to group II. The protective effect of the fitting is created by the amount of liquid remaining in the fitting!
The F-D/F-S type liquid seal detonation arrester may be installed at an arbitrary distance from the location of the probable ignition as a pipe securing.
The F-D/F-S type liquid seal detonation arrester can be installed in the charge and discharge line only in horizontal sections, in such a way that the liquid can not be drained because of the swing due to the motional energy of the liquid flow.
The fitting is not symmetrical concerning its operation. The liquid seal detonation arrester's vessel should stand vertically upwards, considering the side of possible ignition (see data sheet: protected side, unprotected side).
Maximum liquid flow rates:
vmax40 = 5.35 m/s (qmax40=0.44 m3/min)
vmax 50 = 3.16 m/s (qmax50=0.42 m3/min)
vmax 80 = 2.47 m/s (qmax80=0.8 m3/min)
Calculated with a liquid of ρ = 0.7 g/cm3 density
(In case of liquids of higher density these values are greater.)
In case of systems having higher liquid flow rate a coordination with the manufacturer is required prior to designing.
2. Structural elements and material of the F-D/F-S type liquid seal detonation arresters
All structural elements can be made of carbon steel and/or acid-proof steel, expect the flame filter element, which can be made only of acid-proof steel. The gaskets are made of Teflon, but they may be made of other materials, depending on the liquid delivered.
1. Flame filter unit
2. Hole for drain
3. Data table
Protected side
3. Datat table marking:
4. Conditions of the safe use of the F-D/F-S type liquid seal detonation arresters
- A great care should be taken for selecting the location and devices of the installation of the F-D/F-S type liquid seal detonation arrester.
- The F-D/F-S type liquid seal detonation arrester may be installed only in such systems, in which materials belonging to application category IIA may cause the formation of explosive vapour/(gas) - air mixture.
- The fitting is may be installed only in a pipeline of dimension corresponding to the rated connection diameter (application of pipe reducer and/or inverted reducer is not allowed!)
- When installed into the system no leakage is allowed (in case of liquid flow) along the joining flanges at an absolute pressure of 1.1 times absolute working pressure, but minimum 150 kPa.
- If not only liquid phase is present in the charging pipe, then the working pressure may only be atmospheric (according to MSZ EN 12874:2001, item 7.3 the operational pressure of the liquid seal detonation arresters may only be atmospheric upon the arising of explosion risk)
- The allowed surface temperature of the F-D/F-S type liquid seal detonation arrester is: -20ºC ≤ T≤ 60ºC, where the delivered material enables this without damage or the stopping of the protective ability of the fitting. The physical properties of the delivered material should always be taken into consideration e.g.:
freezing-point: risk of freezing, clogging, cracking
boiling point: risk of evaporation of the sealing fluid
vapour pressure: risk of explosion due to ambient temperature
- Prolonged air flow evaporates the protective liquid being in the pipeline! It should be taken into consideration upon designing and operation. (system designing, operating instructions)
- The F-D/F-S type liquid seal detonation arrester can be installed at an arbitrary distance from the location of the probable possible ignition.
- When a leakage occurs at the charging / draining screw of the F-D/F-S type liquid seal detonation arrester, then it should immediately be stopped (tightening the screw or replacing the sealing).
- When a detonation took place in the pipeline, or marks of damage can be seen on the fitting, the fitting should be transported to the manufacturer to be inspected.
- The fitting should be protected from „non-liquid” contaminations. In case of clogging of the flame filter elements such a condition may develop, when the liquid being present in the fitting may be drained due to the static pressure and therefore it may loose its protective effect. When designing the position of installation and/or during the operation a special emphasis should be laid on it, a filtering installation (pl.: pipe filter or filter bowl) should be applied if necessary.
- In case of assemblage for checking and cleaning purpose and removal of the detonation arrester only such tools may be used, which correspond to the zone category, and not generating spark. The assemblage and installation may be performed only by specially qualified persons! Materials (e.g. wiping cloth) causing electrostatic charging should be avoided.
- The removal of the cover and flame filter elements makes a direct interconnection between the protected side and the unprotected, as well as neighbouring atmosphere, so in this case the protected side should previously be shut with a gate valve!
- Prior to draining the fitting the protected side should be closed with a gate valve! The protective effect ceases upon the draining of the fitting!
- If the system having the detonation arrester built in distributes a harmful material, then in case of opening the system due to removal, checking or cleaning purpose the health regulations (e.g. use of respiratory apparatus) should strictly be observed.
Material quality:
Housing : stainless-steel, carbon-steel
Flamefilter: stainless-steel, Hastelloy
Seal: Teflon
Other technical parameters:
„Airspace” of flamefilter: 0,5 mm
Number of flamefilters: 3
Protection: IIA gas group
Labelling:
MKEH-MFI (Hungarian Treade Licencing Office)
Certificate No.: 2/2570-07/06
BKI EX VÁ Robbanásbiztos Berendezéseket Vizsgáló Állomása Kft. (Testing Station for Explosion Proof Equipment)
Certificate No.: BKI 06 ATEX017X
NA40 – NA80 in-line:
Installation dimensions of the assemblyFlange connection (DIN2633)
„A” / „B” / „C” / „D”
DN40 / 285 mm / 448 mm / 168,3 mm
DN50 / 285 mm / 448 mm / 168,3 mm
DN80 / 400 mm / 574 mm / 273 mm
Volume data of the fittings
Flange connection (DIN2633) / Total volume [] / Residual volume [] / Minimum operating volume* []
DN40 / 8,5 / 5,1 / 4,3
DN50 / 8,6 / 5 / 4,2
DN80 / 27,8 / 17,8 / 15,6
* Volume of liquid amount necessary to achieve the protective effect.
Flow-technique measurings DN40 – DN80:
This volume flow/pressure drop diagram has been measured on MSZ ISO 5167-1. The volume flow q in Nm3/min refers to air with density ρair=1,29 kg/m3 at a temperature T0=273 K and pressure p0=1000 mbar.
Conversion factor method on different density media: Δp xy = (ρ xy / ρair) * Δpair
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Földfém Kft. 2005