Avalon Fire Engineering

How Water Mist Suppresses Fire:

Water Mist Systems use far less water than traditional sprinkler systems and operate with smaller-diameter piping, making them highly efficient and easier to install in many applications.

They work by releasing extremely small water droplets—typically 10 µm to 1000 µm—through specialized nozzles operating under controlled pressure.
These ultra-fine droplets suppress fire through three key mechanisms:

1. Fast Cooling:

Because the droplets are extremely small, they have a much larger surface area. This allows them to absorb heat very quickly and turn into steam almost immediately. As the droplets evaporate, they remove a large amount of heat from the fire and rapidly bring down the temperature.

2. Oxygen Reduction:

When the droplets turn into steam, they expand by approximately 1,700 times in volume. This expansion displaces oxygen away from the fire zone. With less oxygen available , the fire’s combustion process is significantly disrupted.

3. Blocking Radiant Heat:

The mist creates a cloud of fine droplets that acts like a barrier. This barrier reduces the heat radiation coming from the fire, slowing its spread and lowering the chance of re-ignition.

By combining cooling, oxygen displacement, and radiant heat reduction, Water Mist Systems control and suppress fires much more efficiently than traditional sprinkler systems.

NFPA ̲𝟖̲𝟎̲ ̲–̲ ̲𝐅̲𝐢̲𝐫̲𝐞̲ ̲𝐃̲𝐨̲𝐨̲𝐫̲ ̲𝐈̲𝐧̲𝐬̲𝐩̲𝐞̲𝐜̲𝐭̲𝐢̲𝐨̲𝐧̲ ̲𝐑̲𝐞̲𝐪̲𝐮̲𝐢̲𝐫̲𝐞̲𝐦̲𝐞̲𝐧̲𝐭̲𝐬̲

NFPA 𝟴𝟬 𝗦𝘁𝗮𝗻𝗱𝗮𝗿𝗱 𝗳𝗼𝗿 𝗙𝗶𝗿𝗲 𝗗𝗼𝗼𝗿𝘀 𝗮𝗻𝗱 𝗢𝘁𝗵𝗲𝗿 𝗢𝗽𝗲𝗻𝗶𝗻𝗴 𝗣𝗿𝗼𝘁𝗲𝗰𝘁𝗶𝘃𝗲𝘀 𝗺𝗮𝗻𝗱𝗮𝘁𝗲𝘀 𝘁𝗵𝗮𝘁 𝗮𝗹𝗹 𝗳𝗶𝗿𝗲 𝗱𝗼𝗼𝗿 𝗮𝘀𝘀𝗲𝗺𝗯𝗹𝗶𝗲𝘀 𝘂𝗻𝗱𝗲𝗿𝗴𝗼 𝗯𝗼𝘁𝗵 𝘃𝗶𝘀𝘂𝗮𝗹 𝗶𝗻𝘀𝗽𝗲𝗰𝘁𝗶𝗼𝗻 𝗮𝗻𝗱 𝗼𝗽𝗲𝗿𝗮𝘁𝗶𝗼𝗻𝗮𝗹 𝘁𝗲𝘀𝘁𝗶𝗻𝗴 𝗮𝘁 𝘁𝗵𝗲 𝗳𝗼𝗹𝗹𝗼𝘄𝗶𝗻𝗴 𝗶𝗻𝘁𝗲𝗿𝘃𝗮𝗹𝘀:

🔴 𝗨𝗽𝗼𝗻 𝗰𝗼𝗺𝗽𝗹𝗲𝘁𝗶𝗼𝗻 𝗼𝗳 𝗮 𝗻𝗲𝘄 𝗶𝗻𝘀𝘁𝗮𝗹𝗹𝗮𝘁𝗶𝗼𝗻
🔴 𝗔𝗻𝗻𝘂𝗮𝗹𝗹𝘆, 𝗮𝘀 𝗽𝗮𝗿𝘁 𝗼𝗳 𝘁𝗵𝗲 𝗿𝗲𝗾𝘂𝗶𝗿𝗲𝗱 𝗽𝗲𝗿𝗶𝗼𝗱𝗶𝗰 𝗶𝗻𝘀𝗽𝗲𝗰𝘁𝗶𝗼𝗻
🔴 𝗔𝗳𝘁𝗲𝗿 𝗮𝗻𝘆 𝗺𝗮𝗶𝗻𝘁𝗲𝗻𝗮𝗻𝗰𝗲 𝗼𝗿 𝗰𝗼𝗿𝗿𝗲𝗰𝘁𝗶𝘃𝗲 𝘄𝗼𝗿𝗸 𝗵𝗮𝘀 𝗯𝗲𝗲𝗻 𝗽𝗲𝗿𝗳𝗼𝗿𝗺𝗲𝗱

𝗧𝗼 𝗰𝗼𝗺𝗽𝗹𝗲𝘁𝗲 𝗮 𝗰𝗼𝗺𝗽𝗹𝗶𝗮𝗻𝘁 𝘃𝗶𝘀𝘂𝗮𝗹 𝗶𝗻𝘀𝗽𝗲𝗰𝘁𝗶𝗼𝗻, 𝘁𝗵𝗲 𝗳𝗼𝗹𝗹𝗼𝘄𝗶𝗻𝗴 𝗽𝗼𝗶𝗻𝘁𝘀 𝗺𝘂𝘀𝘁 𝗯𝗲 𝘃𝗲𝗿𝗶𝗳𝗶𝗲𝗱:

1️⃣ 𝗗𝗼𝗼𝗿 𝗹𝗮𝗯𝗲𝗹𝘀 𝗮𝗿𝗲 𝗽𝗿𝗲𝘀𝗲𝗻𝘁, 𝘃𝗶𝘀𝗶𝗯𝗹𝗲, 𝗮𝗻𝗱 𝗹𝗲𝗴𝗶𝗯𝗹𝗲.
2️⃣ 𝗡𝗼 𝗼𝗽𝗲𝗻 𝗵𝗼𝗹𝗲𝘀, 𝗰𝗿𝗮𝗰𝗸𝘀, 𝗼𝗿 𝗯𝗿𝗲𝗮𝗸𝘀 𝗮𝗿𝗲 𝗽𝗿𝗲𝘀𝗲𝗻𝘁 𝗼𝗻 𝘁𝗵𝗲 𝗱𝗼𝗼𝗿 𝗼𝗿 𝗳𝗿𝗮𝗺𝗲.
3️⃣ 𝗩𝗶𝘀𝗶𝗼𝗻 𝗽𝗮𝗻𝗲𝗹𝘀, 𝗴𝗹𝗮𝘇𝗶𝗻𝗴, 𝗳𝗿𝗮𝗺𝗲𝘀, 𝗮𝗻𝗱 𝗯𝗲𝗮𝗱𝘀 𝗮𝗿𝗲 𝗶𝗻𝘁𝗮𝗰𝘁 𝗮𝗻𝗱 𝘀𝗲𝗰𝘂𝗿𝗲𝗹𝘆 𝗳𝗮𝘀𝘁𝗲𝗻𝗲𝗱.
4️⃣ 𝗧𝗵𝗲 𝗱𝗼𝗼𝗿, 𝗵𝗶𝗻𝗴𝗲𝘀, 𝗵𝗮𝗿𝗱𝘄𝗮𝗿𝗲, 𝗳𝗿𝗮𝗺𝗲, 𝗮𝗻𝗱 𝗻𝗼𝗻-𝗰𝗼𝗺𝗯𝘂𝘀𝘁𝗶𝗯𝗹𝗲 𝘁𝗵𝗿𝗲𝘀𝗵𝗼𝗹𝗱 𝗮𝗿𝗲 𝗽𝗿𝗼𝗽𝗲𝗿𝗹𝘆 𝗮𝗹𝗶𝗴𝗻𝗲𝗱, 𝘀𝗲𝗰𝘂𝗿𝗲, 𝗮𝗻𝗱 𝗳𝗿𝗲𝗲 𝗳𝗿𝗼𝗺 𝘃𝗶𝘀𝗶𝗯𝗹𝗲 𝗱𝗮𝗺𝗮𝗴𝗲.
5️⃣ 𝗗𝗼𝗼𝗿 𝗰𝗹𝗲𝗮𝗿𝗮𝗻𝗰𝗲𝘀 𝗱𝗼 𝗻𝗼𝘁 𝗲𝘅𝗰𝗲𝗲𝗱 𝘁𝗵𝗲 𝗹𝗶𝗺𝗶𝘁𝘀 𝗽𝗲𝗿𝗺𝗶𝘁𝘁𝗲𝗱 𝗯𝘆 NFPA 𝟴𝟬 (𝗦𝗲𝗰𝘁𝗶𝗼𝗻𝘀 𝟰.𝟴.𝟰 𝗮𝗻𝗱 𝟲.𝟯.𝟭.𝟳)
6️⃣ 𝗡𝗼 𝗰𝗼𝗺𝗽𝗼𝗻𝗲𝗻𝘁𝘀 𝗼𝗳 𝘁𝗵𝗲 𝗱𝗼𝗼𝗿 𝗮𝘀𝘀𝗲𝗺𝗯𝗹𝘆 𝗮𝗿𝗲 𝗯𝗿𝗼𝗸𝗲𝗻, 𝗱𝗮𝗺𝗮𝗴𝗲𝗱, 𝗼𝗿 𝗺𝗶𝘀𝘀𝗶𝗻𝗴.
7️⃣ 𝗦𝗲𝗹𝗳-𝗰𝗹𝗼𝘀𝗶𝗻𝗴 𝗱𝗲𝘃𝗶𝗰𝗲𝘀 𝗼𝗽𝗲𝗿𝗮𝘁𝗲 𝗰𝗼𝗿𝗿𝗲𝗰𝘁𝗹𝘆, 𝗲𝗻𝘀𝘂𝗿𝗶𝗻𝗴 𝘁𝗵𝗲 𝗱𝗼𝗼𝗿 𝗳𝘂𝗹𝗹𝘆 𝗰𝗹𝗼𝘀𝗲𝘀 𝗳𝗿𝗼𝗺 𝘁𝗵𝗲 𝗳𝘂𝗹𝗹𝘆 𝗼𝗽𝗲𝗻 𝗽𝗼𝘀𝗶𝘁𝗶𝗼𝗻.
8️⃣ 𝗟𝗮𝘁𝗰𝗵𝗶𝗻𝗴 𝗵𝗮𝗿𝗱𝘄𝗮𝗿𝗲 𝗶𝘀 𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻𝗮𝗹 𝗮𝗻𝗱 𝘀𝗲𝗰𝘂𝗿𝗲𝗹𝘆 𝗹𝗮𝘁𝗰𝗵𝗲𝘀 𝘁𝗵𝗲 𝗱𝗼𝗼𝗿 𝘄𝗵𝗲𝗻 𝗰𝗹𝗼𝘀𝗲𝗱.
9️⃣ 𝗡𝗼 𝗮𝘂𝘅𝗶𝗹𝗶𝗮𝗿𝘆 𝗵𝗮𝗿𝗱𝘄𝗮𝗿𝗲 𝗶𝘀 𝗶𝗻𝘀𝘁𝗮𝗹𝗹𝗲𝗱 𝘁𝗵𝗮𝘁 𝗿𝗲𝘀𝘁𝗿𝗶𝗰𝘁𝘀 𝗼𝗿 𝗶𝗻𝘁𝗲𝗿𝗳𝗲𝗿𝗲𝘀 𝘄𝗶𝘁𝗵 𝗽𝗿𝗼𝗽𝗲𝗿 𝗱𝗼𝗼𝗿 𝗼𝗽𝗲𝗿𝗮𝘁𝗶𝗼𝗻.
🔟 𝗧𝗵𝗲 𝗱𝗼𝗼𝗿 𝗮𝘀𝘀𝗲𝗺𝗯𝗹𝘆 𝗰𝗼𝗺𝗽𝗹𝗶𝗲𝘀 𝘄𝗶𝘁𝗵 𝗲𝗱𝗴𝗲 𝗽𝗿𝗼𝘁𝗲𝗰𝘁𝗶𝗼𝗻, 𝗲𝗱𝗴𝗲 𝘀𝗲𝗮𝗹𝘀, 𝗮𝗻𝗱 𝗴𝗮𝘀𝗸𝗲𝘁𝗶𝗻𝗴 𝗿𝗲𝗾𝘂𝗶𝗿𝗲𝗺𝗲𝗻𝘁𝘀.

𝗘𝗻𝘀𝘂𝗿𝗶𝗻𝗴 𝗳𝗶𝗿𝗲 𝗱𝗼𝗼𝗿𝘀 𝗮𝗿𝗲 𝗽𝗿𝗼𝗽𝗲𝗿𝗹𝘆 𝗶𝗻𝘀𝗽𝗲𝗰𝘁𝗲𝗱 𝗮𝗻𝗱 𝗺𝗮𝗶𝗻𝘁𝗮𝗶𝗻𝗲𝗱 𝗶𝘀 𝗰𝗿𝗶𝘁𝗶𝗰𝗮𝗹 𝘁𝗼 𝗹𝗶𝗳𝗲 𝘀𝗮𝗳𝗲𝘁𝘆 𝗮𝗻𝗱 𝗰𝗼𝗱𝗲 𝗰𝗼𝗺𝗽𝗹𝗶𝗮𝗻𝗰𝗲. 𝗥𝗲𝗴𝘂𝗹𝗮𝗿 𝗶𝗻𝘀𝗽𝗲𝗰𝘁𝗶𝗼𝗻𝘀 𝗻𝗼𝘁 𝗼𝗻𝗹𝘆 𝘀𝘂𝗽𝗽𝗼𝗿𝘁 𝗳𝗶𝗿𝗲 𝗽𝗿𝗼𝘁𝗲𝗰𝘁𝗶𝗼𝗻 𝗽𝗲𝗿𝗳𝗼𝗿𝗺𝗮𝗻𝗰𝗲 𝗯𝘂𝘁 𝗮𝗹𝘀𝗼 𝗲𝗻𝗵𝗮𝗻𝗰𝗲 𝘁𝗵𝗲 𝗼𝘃𝗲𝗿𝗮𝗹𝗹 𝘀𝗮𝗳𝗲𝘁𝘆 𝗼𝗳 𝘁𝗵𝗲 𝗯𝘂𝗶𝗹𝘁 𝗲𝗻𝘃𝗶𝗿𝗼𝗻𝗺𝗲𝗻𝘁.

Sprinkler design can be easily misunderstood:-

BS EN12845 and MS1910
1. Never mix precalculated sprinkler design with hydraulically calculated design. Pre calculated design allows all range pipes and distribution pipe serving sprinkler points downstream of design point to be specified to pipe schedule. It then does calculation for pressure loss from control valve to design point including static gain and limit to say 500mbar for OH design with flow rate of 1000L/min. Note that design point shall be specified in every floor.

2. When doing hydraulic calculation design, we need to consider most favourable and unfavourable AMAO area. Start with hydraulically most unfavourable area with pressure greater than 7psi. And then work out the flow rate as per pipe size assigned and pressure available at upstream sprinkler points. This will allow you to work out the minimum design flow rate. And your pump flow rate will also need to cater for sprinklers discharging at the most favourable area.

3. Hydraulic calculation design is required for rack sprinklers, ESFR sprinklers, looped design. Pipe schedule method cannot be used.

4. HHP and HHS precalculated design calculation is based on pressure required not at control valve but at highest sprinkler point. Then you can work out your pump pressure to deliver the required flow rate and pressure.

5. Fire pumps are set based on shut off pressure and not your design pressure.

As for me, I do not see the point of doing full hydraulic calculation to down size pipe design which can be carried out as precalculated/ pipe schedule design. Hydraulic calculation is just very tedious unless you use software such as sprinkcal.

Click to register and learn about sprinkler design.

Understanding the FM200 Gauge for Fire Suppression Systems

The FM200 fire suppression system relies on HFC-227ea, stored in pressurized cylinders, to protect critical environments like data centers and server rooms. A key component is the pressure and temperature gauge, designed to monitor cylinder conditions. Here’s a breakdown:

Below I (Red): Pressure/temperature below minimum operating levels—recharge required.

I to II (Red): Pressure below 95% of normal (e.g., 360 psi at 70°F/21°C)—still operable, but monitor closely.

II to III (Green): Pressure between 95% and 110% of normal—system is fully operational.

III to IV (Red): Pressure above 110%—operable but check for over-pressurization.

Over IV (Red): Above maximum temperature/pressure—overcharged, remove from service.

Key Tips:
Check semi-annually per NFPA 2001 standards.
Adjust for temperature (pressure rises ~1.5-2 psi/°F above 70°F).
Ensure certified maintenance for recharging or overcharge issues.
Stay proactive with FM200 maintenance to ensure safety and compliance!

ফায়ার ডোর – কি কি চেক করতে হয় যা বাংলাদেশ কোডে খুব বেশী বলা নেই

1. NFPA 80 অনুসারে ফায়ার ডোর কতবার পরিদর্শন করতে হয়? ইনস্টলেশনের পর এবং তারপর প্রতি বছর অন্তত একবার। NFPA 80, Sec. 5.2.1

2. কে পরিদর্শন করতে পারে? প্রশিক্ষিত ও যোগ্য ব্যক্তি যার ফায়ার ডোর অ্যাসেম্বলি সম্পর্কিত জ্ঞান আছে। NFPA 80, Sec. 3.3.95

3. রিপোর্ট কতদিন সংরক্ষণ করতে হবে? অন্তত ৩ বছর। NFPA 80, Sec. 5.2.1.5

4. কোন কোন বিষয় চেক করতে হয়? গর্ত, ফাটল, সীল, হার্ডওয়্যার, ক্লোজিং ডিভাইস, লেবেল, গ্যাপ। NFPA 80, Sec. 5.2.3

5. ফায়ার ডোরের লেবেল কোথায় থাকে? দরজার হিঞ্জ সাইডের উপরের অংশ ও ফ্রেমে। NFPA 80, Sec. 4.2.1

6. অনুমোদন ছাড়া ফিল্ড মডিফিকেশন করা যাবে কি? না, AHJ বা লিস্টিং এজেন্সির অনুমোদন লাগবে। NFPA 80, Sec. 4.1.3

7. ফায়ার ডোরের নিচের সর্বোচ্চ ফাঁকা কত? সর্বোচ্চ ৩/৪ ইঞ্চি (থ্রেশোল্ড ছাড়া)। NFPA 80, Sec. 4.8.4

8. ফায়ার ডোর কাজ না করলে করণীয় কী? অবিলম্বে মেরামত বা প্রতিস্থাপন। NFPA 80, Sec. 5.2.1.4

9. রোলিং স্টিল ফায়ার ডোরের টেস্ট কবে? বার্ষিক ড্রপ টেস্ট এবং ইনস্পেকশন। NFPA 80, Sec. 5.2.3.5

10. ইনস্পেকশন রিপোর্ট ফরম্যাট? নির্দিষ্ট নয়, তবে সব প্রয়োজনীয় আইটেম থাকতে হবে। NFPA 80, Sec. 5.2.1.6

11. ত্রুটি থাকলে CO দেওয়া যাবে কি? না, সংশোধন শেষে দেওয়া হবে। AHJ Policy NFPA 80

12. সার্টিফিকেশন মেয়াদ কত? সাধারণত ৩–৫ বছর, পুনঃসার্টিফিকেশন প্রয়োজন। NFPA 80 Commentary

13. গ্লাস/গ্লেজিং চেক করা লাগে কি? হ্যাঁ, অক্ষত থাকতে হবে। NFPA 80, Sec. 4.4

14. গ্যাপ সীমা কত? সাইড ও হেডে 1/8"–3/16", বটমে 3/4"। NFPA 80, Sec. 6.3.1

15. NFPA 80 কি শুধু দরজা কভার করে? না, পুরো অ্যাসেম্বলি কভার করে। NFPA 80, Sec. 1.1

16. ফায়ার ডোর স্বয়ংক্রিয়ভাবে বন্ধ হবে কি? হ্যাঁ, স্ব-ক্লোজিং বা অটো-ক্লোজিং ডিভাইস থাকতে হবে। NFPA 80, Sec. 6.1.4

17. প্যানিক হার্ডওয়্যার লাগানো যাবে কি? হ্যাঁ, যদি লিস্টেড ও অনুমোদিত হয়। NFPA 80, Sec. 6.4.1

18. কী ধরনের সীল লাগবে? লিস্টেড ও রেটিং অনুযায়ী উপযুক্ত সীল। NFPA 80, Sec. 3.3.107

19. ডোর স্টপ বা হোল্ড ওপেন ডিভাইস লাগানো যাবে কি? শুধু লিস্টেড ও ফায়ার ডোরের জন্য অনুমোদিত হলে। NFPA 80, Sec. 6.1.3.1

20. কিক প্লেট লাগানোর নিয়ম কী? উচ্চতা সর্বোচ্চ দরজার উচ্চতার 16" পর্যন্ত, এবং লিস্টেড হতে হবে। NFPA 80, Sec. 4.2.13

21. ডোর ফ্রেম কিসের হতে হবে? ফায়ার রেটেড ও লিস্টেড ম্যাটেরিয়াল। NFPA 80, Sec. 4.1.4

22. ফায়ার ডোরে পেইন্ট করা যাবে কি? হ্যাঁ, তবে লেবেল ঢেকে যাবে না। NFPA 80, Sec. 4.2.2

23. কেবল পাস করানো যাবে কি? না, অনুমোদিত পেনিট্রেশন ছাড়া নয়। NFPA 80, Sec. 4.8

24. গ্লাস কত মিনিট রেটেড হবে? ডোর রেটিং এর সমান বা বেশি। NFPA 80, Sec. 4.4.5

25. লুভার লাগানো যাবে কি? হ্যাঁ, যদি লিস্টেড হয় এবং ডোরের রেটিং বজায় থাকে। NFPA 80, Sec. 4.4.4

26. ডোরের ন্যূনতম পুরুত্ব কত? রেটিং অনুসারে, সাধারণত 1-3/4"। NFPA 80, Sec. 4.2.3

27. ডাবল লিফ ডোরে অ্যাস্ট্রাগাল লাগানো লাগবে কি? হ্যাঁ, রেটিং অনুযায়ী। NFPA 80, Sec. 3.3.7

28. ডোরে সাইন লাগানো যাবে কি? হ্যাঁ, যদি 5 বর্গফুটের কম হয় ও লিস্টেড হয়। NFPA 80, Sec. 4.1.4.2

29. গ্যাপ গেজ ব্যবহার করা বাধ্যতামূলক কি? সুপারিশকৃত, সঠিক মাপ নিশ্চিতের জন্য। NFPA 80 Commentary

30. স্বয়ংক্রিয় ডোর রিলিজ কবে কাজ করবে? অ্যালার্ম বা স্প্রিংকলার অ্যাক্টিভেশনে। NFPA 80, Sec. 6.1.3.3

We have often seen discussions around how far fire hydrants should be placed away from buildings. While codes such as NFPA 24 prescribe minimum clearances (typically 40 ft), one reference that can be considered as a best practice is the collapse zone requirement from NFPA 1500.

NFPA 1500 (2021), Section 8.7.4.4.4.2 states:
“Collapse zones shall be established around the perimeter of the building at a distance that is equal to a minimum of 1.5 times the height of the building.”
Example: For a 20 ft high wall, the collapse zone extends to 30 ft.
If we consider this principle, hydrants located beyond the collapse zone not only comply with NFPA 24 but also ensure that firefighters and apparatus have safe access without being exposed to structural failure hazards.

While the 1.5× rule is a fundamental principle, it is not a one-size-fits-all solution, especially for high-rise buildings where falling glass, facade elements, and debris can extend hazards well beyond the calculated zone. Context, building type, and local fire department operations must always be considered.

Best practice takeaway: Position hydrants where they serve operational needs, support the fire department connection (FDC), and remain outside potential collapse zones for firefighter safety.

This is an area where design, code compliance, and firefighter safety truly intersect.

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ressure Sensing Line – NFPA 20 Requirements

The pressure sensing line is a critical component in fire pump installations. According to NFPA 20, proper design and installation are essential for reliable performance:

Use brass, rigid copper pipe or stainless steel tubing (½ inch).
Install two bronze/stainless steel check valves at least 1.52 m apart with a drilled hole for dampening.
No shutoff valve is allowed in the sensing line.
Provide two inspection test valves for functionality checks.

Compliance with NFPA 20 ensures accurate pressure sensing, prevents false pump operations, and improves system reliability.

Protection Areas per Sprinkler.

The protection area of coverage per sprinkler (As) shall be determined as follows:

(1) Along branch lines as follows:
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(a) Determine distance between sprinklers (or to wall or obstruction in the case of the end sprinkler on the branch line) upstream and downstream
(b) Choose the larger of either twice the distance to the wall or the distance to the next sprinkler
(c) Define dimension as S

(2) Between branch lines as follows:
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(a) Determine perpendicular distance to the sprinkler on the adjacent branch line (or to a wall or obstruction in the case of the last branch line) on each side of the branch line on which the subject sprinkler is positioned
(b) Choose the larger of either twice the distance to the wall or obstruction or the distance to the next sprinkler
(c) Define dimension as L

The protection area of coverage of the sprinkler shall be established by multiplying the S dimension by the L dimension, as follows:
As = S × L

Example:
---------
Exhibit 8.6 illustrates the various measurements that must be considered when determining the S andL dimensions. As shown in Exhibit 8.6, for the S dimension, if two times A is greater than B, then two times A is used as the S dimension. However, if B is greater than two times A, then B is used as the S dimension.
If A × 2 > B, then A × 2 = S
If B > A × 2, then B = S
For the L dimension, if D is greater than two times C, then D is used as the L dimension, but if two times C is greater than D, then two times C is used as the L dimension.
If C × 2 > D, then C × 2 = L
If D > C × 2, then D = L

Exhibit 8.7 provides a specific example with the following results:
S = the larger of 15 ft (4.6 m) or 3 ft (900 mm) · 2, therefore, S = 15 ft (4.6 m)
L = the larger of 10 ft (3 m) or 6 ft (1.8 m) · 2, therefore, L = 12 ft (3.7 m)
The area per sprinkler (S · L) is then 15 ft · 12 ft (4.6 m · 3.7 m) or 180 ft2 (17 m2).

It is important to understand that the S or L dimension is always the greater of the two dimensions (2 times the distance to a wall or obstruction or the distance between sprinklers) because over-spacing sprinklers can result in under-discharging the prescribed volume of water for the area protected by individual sprinklers along a wall or obstruction.

Reference: NFPA 13.

Clean Agent Fire Suppression Systems

In mission-critical environments like server rooms, control centers, and sensitive electrical installations, traditional water-based suppression systems can cause more damage than fire itself. That’s where Clean Agent Fire Suppression Systems come into play!

These systems:
1- Provide fast and effective fire suppression.
2- Are safe for sensitive electronic equipment.
3- Leave no residue – zero clean-up downtime.
4- Comply with international standards such as NFPA 2001.
5- Ideal for applications in Data Centers, Control Rooms, Archives, and Telecom Facilities.

Whether you’re designing for a high-risk environment or enhancing fire safety for existing infrastructure, clean agent systems offer reliability without compromise.

Fire Sprinkler Systems – What, Why, and How (NFPA 13 & NFPA 25)

What Is a Wet Sprinkler System (NFPA 13 – Section 3.3.244.1):

A wet sprinkler system is one in which the piping is constantly filled with water under pressure. When the ambient temperature reaches the rated activation point (typically 155°F or 68°C), the sprinkler head activates, and water discharges immediately to suppress or control the fire.

Why Fire Sprinkler Systems Are Critical

Fire sprinkler systems are essential for early fire suppression. According to NFPA studies, they can reduce fire-related deaths by up to 80% and significantly limit property damage. They:
• Respond automatically without human intervention
• Confine fire spread to the point of origin
• Protect personnel and assets
• Ensure compliance with codes and insurance policies

Main Components of a Wet Sprinkler System
1. Sprinkler Heads – Heat-sensitive elements that open when a specific temperature is reached
2. Piping Network – Filled with water under pressure, connected to the sprinkler heads
3. Control Valve – Controls the water supply to the system
4. Alarm Valve – Triggers water flow alarm when system activates
5. Pressure Gauges – Monitor water pressure before and after alarm valve
6. Water Flow Switch – Sends signal to FACP when flow is detected
7. Test Valve – Used to simulate sprinkler discharge during tests
8. Drain Valve – Allows drainage of the system during maintenance

Inspection, Testing & Maintenance (as per NFPA 25)
• Monthly
• Visual inspection of valves, gauges, and tamper switches
• Quarterly
• Test water flow alarm using test valve
• Verify operation of tamper and flow switches
• Annually
• Full functional test of the system
• Main drain test for pressure verification
• Every 5 Years
• Internal pipe inspection for corrosion or obstructions

All testing must follow NFPA 25 procedures and be documented by qualified personnel.

Summary

Wet sprinkler systems are reliable, fast-acting, and low-maintenance. Designed and maintained according to NFPA 13 and NFPA 25, they form the backbone of active fire protection in commercial and industrial facilities.