Discharges Tab Page
- On this tab page the details of all operating sprinklers/nozzles, hydrants/standpipe or fixed discharges that are to be entered in the long hand form are entered.
The buttons on the Tool Bar for this page are
- Close - exits this screen
- Show Errors
- Deletes the current line of Sprinkler/Nozzle or Fixed Discharge data
- Add a sequential group of Sprinklers/Nozzles - does not apply to Discharges nor adding single sprinklers/nozzles. Note when display is All, single Sprinklers or Nozzles can be added by going to the last line which will be blank ready for input.
- ? Help on the current tab page.
- Display Sprinklers & Nozzles – All or Compressed:
- Display Sprinklers & Nozzles: A radio button to allow the sprinklers and nozzles to be displayed one per line (All) or in groups (Compressed) with the same characteristics; Node n to Node m (including all nodes with sequential numbers between).
- Note that to save time editing, data values can be changed whilst in compressed mode and then all sprinklers or nozzles from Node n to Node m will be changed.
Sprinklers/Nozzles
The items that are entered for each sprinkler/nozzle are:
Node No. (when display is All): The node number (between 1 and 9999) of the sprinkler or nozzle.
From Node No., To Node No. (when display is Compressed): The first and last node number of a sequential group of sprinklers or nozzles with exactly the same characteristics.
Type - Sprinkler or Nozzle
Elevation: The elevation of the node above or below a given datum in units as specified in the Project Tab Page. If left blank in the Sprinkler and Nozzles, Hydrants/Standpipes or Reference nodes data, the program assumes the default value above the column heading.
Minimum Flow: The required flow of the sprinkler in units of flow as specified in the Project Tab Page. If Calculate Input OR Booster Pump Flow and Pressure is being used it is the minimum flow. If it is Calculate Discharge Flows for Given Input, it may be adjusted up or down depending on the entered pressure at the input point(s). If left blank, the program assumes the default above the column heading.
k Factor:
The sprinkler constant as given by the manufacturer. If left blank in the data for Sprinkler/Nozzles on the Discharge Tab Page, the program assumes the default above the column heading. k is the ratio of the sprinkler discharge divided by the square root of the pressure drop of the sprinkler or nozzle.
i.e. k = Q /√ PThe sprinkler constant entered must be consistent with the units of flow and pressure specified in the Project Tab Page.
The following table lists typical values of k for various sprinklers:
Sprinkler Orifice Size mm (ins) Sprinkler constant k with units of flow and pressure of: l/min & kPa l/sec & kPa USGPM & PSI L/min & Bar Commercial 10 (3/8) 5.70 0.095 4.0 57.0 15 (1/2) 8.00 0.133 5.6 80.0 20 (3/4) 11.50 0.192 8.0 115.0 Domestic 9.5 (3/8) 4.00 0.067 2.8 40.0 11.1 (7/16) 6.00 0.100 4.2 60.0 12.7 (½) 8.00 0.133 5.6 80.0 13.5 (17/32) 11.70 0.195 8.1 117.0 The following table lists typical values of k and the pressure exponent for various atomizer nozzles.
Nozzle Type Constant k with units of flow and pressure of: Pressure Exponent l/min & kPa l/sec & kPa USGPM & PSI L/min & Bar Swirl Type 0.10 0.0017 0.069 0.995 0.5 Cluster Swirl Type 0.11 0.0018 0.073 1.05 0.5 Spiral 1.37 0.023 0.95 13.7 0.5 Full Cone 1.65 0.027 1.08 14.4 0.47 Wide Angle Full Cone 1.60 0.027 0.99 12.5 0.44
The following table lists typical values of k for various nozzles.
NozzleSize mm(ins) Constant k with units and flow and pressure of: Coeff. of dis-charge l/min & kPa l/sec & kPa USGPM & PSI L/min & Bar 6 (1/4) 2.1 0.035 1.46 21.0 8 (5/16) 3.0 0.050 2.10 30.0 10 (3/8) 4.3 0.071 3.01 43.0 12 (1/2) 0.985 9.5 0.158 6.65 95.0 16 (5/8) 0.985 16.9 0.282 11.8 169.0 19 (3/4) 0.983 23.8 0.396 16.7 238.0 22 (7/8) 0.982 31.8 0.531 22.3 318.0 25 (1) 0.972 40.7 0.678 28.5 407.0 28 (1 1/8) 0.976 51.3 0.854 35.9 513.0 Pressure Exponent
Sprinklers and spray nozzles are designed to produce certain spray characteristics. It is generally accepted in the fire protection industry to use the discharge coefficient (or k factor) when determining the flow through a sprinkler or nozzle. i.e. Q = k x Pn where the pressure exponent n is taken as 0.5. Highly engineered sprays, as opposed to standard deflection type sprinklers, often contain complex internal and external geometries to form the distinctive spray patterns. In order to account for the different flow characteristic of these types of discharges, the pressure exponent can be considered as an input variable rather than a constant.
Typical Pressure exponents are:
Spray/Nozzle Type Pressure Exponent Deflector type Sprinklers 0.50 Swirl Type Atomisers 0.50 Spiral Nozzle 0.50 Full Cone 0.47 Wide Angle Full Cone 0.44 If a value is not entered, the program assumes a default value of 0.50
Operating: Against each Sprinkler/Nozzle and Hydrant/standpipe, this checkbox allows the user to select discharges that are operating or not. Above the column heading is two buttons to Clear all (turn all discharges OFF) or Check All (turn all discharges ON. Hence for example all sprinklers can be entered and then various combinations of operating sprinklers can be selected and the program run to determine which are the most unfavourable and the most favourable. It has also been introduced to assist with selecting the operating sprinklers when downloading a data file fro Revit with the new ACADS-BSG program RHYENA.
Hydrants/Standpipes
The items that are entered for each hydrant/standpipe are:
Node No.: The node numbers across the nth row of the GRID starting from the left hand side including sprinkler nodes and Main Pipe nodes
Elevation: The elevation of the node above or below a given datum in units as specified in the Project Tab Page. If left blank in the Sprinkler and Nozzles, Hydrants/Standpipes or Reference nodes data, the program assumes the default value above the column heading.
Minimum Flow: The required flow of the sprinkler in units of flow as specified in the Project Tab Page. If Calculate Input OR Booster Pump Flow and Pressure is being used it is the minimum flow. If it is Calculate Discharge Flows for Given Input, it may be adjusted up or down depending on the entered pressure at the input point(s). If left blank, the program assumes the default above the column heading.
Min. Pressure: The minimum or residual pressure required at the hydrant/standpipe connection point. This is used with the entered Minimum flow to determine the equivalent k factor. The program then uses this calculated k factor for all the entered hydrants or stand pipes to determine the most remote hydrant/standpipe when Calculate input flow and pressure” is selected on the Project Screen. When “Discharge flows for given input” is selected, the calculated k factor is used to determine the flow based on the pressure at the hydrant/standpipe node.
- Hydrants (From AS2419 – 2005) | Type of Hydrant | Minimum Flow Rate (L/s) | Min. Residual Pressure (kPa) | |-------------------------------------|:-------------------------:|:------------------------------:| |Feed fire hydrant unassisted - NSW | 10 | 150 | |Other States | 10 | 200 | |Attack fire Hydrant, unassisted - NSW| 10 | 250 | |Other States | 10 | 350 | |Internal and external fire hydrant when boosted by a fire brigade pumping appliance|10| 700 | |Attack fire hydrant performance achieved without the use of a fire brigade pumping appliance |5| 700| |Hydrant pumped max pressure | 5 | 1200 | |Hydrant pumped max pressure at valve shut| 0 | 1300 |
- **Hose Reels (from AS2441 - 2005)**
| Nominal Hose Diameter | Minimum Flow Rate || Minimum Required Pressure (+ 10 kPa) |
|:-----------------------------:|:------------------:|:-----------:|:------------------------------------:|
| mm | L/s | L/min | kPa |
| 19 | 0.33 | 20 | 220 |
| 25 | 0.41 | 25 | 220 |
Max. Pressure (optional): The maximum pressure allowed at the hydrant/standpipe connection. This is optional input and is only used in reporting any excessive pressures in the Node Characteristics Results.
Operating: Against each Sprinkler/Nozzle and Hydrant/standpipe, this checkbox allows the user to select discharges that are operating or not. Above the column heading is two buttons to Clear all (turn all discharges OFF) or Check All (turn all discharges ON. Hence for example all sprinklers can be entered and then various combinations of operating sprinklers can be selected and the program run to determine which are the most unfavourable and the most favourable. It has also been introduced to assist with selecting the operating sprinklers when downloading a data file fro Revit with the new ACADS-BSG program RHYENA.
Above the input data table for the sprinklers/nozzles and for the hydrants/standpipe are fields which allow the entry of defaults which apply to any sprinkler/nozzle or hydrant/standpipe where this field is blank: If no defaults are entered for any item (column) then all rows in that column must have values except the Pressure Exponent for Sprinklers/Nozzles and the Maximum Pressure for Hydrants/Standpipes as these are not mandatory fields.
Above the “Operating” column for Sprinklers and Nozzles Hydrants and Standpipes, there are two buttons to Clear All or Check All.
Above the Hydrants/Standpipes Table there are two radio buttons to control whether the flow for the Hydrants/Standpipes are to remain fixed or allowed to vary with pressure.
Fixed Discharges
This brings the Fixed Discharge input data table on screen.
Fixed discharges are nodes that have a fixed discharge. When analyzing a hydrant system a fixed discharge can be used to model a fire hydrant that has a fixed flow regardless of the pressure at the connection point
The items that are entered for each fixed discharge are:
Node No.: The node number of the fixed discharge.
Elevation: The elevation of the node above or below a given datum in units as specified in the Project Tab Page. If left blank in the Sprinkler and Nozzles, Hydrants/Standpipes or Reference nodes data, the program assumes the default value above the column heading.
Discharge: The flow from the fixed discharge (to allow for standpipes, connections to other systems, etc.)