📦 Storage Protection in Sprinkler Systems: Class I-IV and Plastics

📋 Table 20.9.4.2 — What It Means (Explained Simply)

Table Title:
▶️ Maximum Clearance from Top of Storage to Ceiling for CMDA Protection Criteria

What the Table is About:
This table tells you how much empty space you can leave between the top of the stored goods and the ceiling when you’re using CMDA sprinklers (Conventional Mode Density Application sprinklers).

👉 It’s about how close the storage can be to the ceiling before it becomes unsafe or needs a different design!

🧹 Breaking Down Each Row:

🧠 What Each Storage Condition Means:

• Palletized / Solid-Piled / Shelf Storage:
  Goods stacked on pallets or shelves without high racks.
  ✅ 20 ft (6.1 m) clearance allowed for both Class I-IV and Group A Plastics.
• Rack Storage up to 25 ft:
  ✅ 20 ft clearance for Class I-IV.
  ⚠️ Only 10 ft (3.0 m) clearance for Group A Plastics due to higher fire risk!
• Rack Storage over 25 ft:
  ✅ Always 10 ft (3.0 m) clearance, regardless of commodity class, because fire grows faster at this height!

🎯 In Summary:

• 🧺 For simple pile storage (not rack), 20 ft clearance is allowed for everything.
• 🏗️ For rack storage with high fire-risk plastics, reduce clearance to 10 ft!
• 🚀 For tall racks over 25 ft, always keep clearance at 10 ft, no matter the material!

✨ Why Is This Important?

Because if the gap is too big, the fire can grow too much before the sprinklers react.
If the gap is smaller, sprinklers catch and control the fire quicker, reducing damage and saving lives! 🛡️

📋 Table 20.9.4.3 — Class I Through Class IV Commodities (Explained Simply)

Table Title:
▶️ Clearances and In-Rack Sprinkler Options for Storage

What the Table is About:
This table tells you how to handle fire protection when there’s a **large gap between the top of the stored goods and the ceiling**, especially when you are storing Class I-IV commodities (ordinary goods like paper, fabrics, wood, etc.).

👉 It also tells when you are allowed to use in-rack sprinklers instead of depending only on ceiling sprinklers!

🧹 Breaking Down Each Row:

🧠 What Each Storage Configuration Means:

• Palletized / Solid-Piled / Shelf Storage:
  ✅ You’re fine as long as the clearance doesn’t exceed 20 ft (6.1 m). No special in-rack sprinklers are needed!
• Rack Storage up to 25 ft:
  ✅ If the clearance is more than 20 ft, you can either redesign based on that huge gap OR you can add in-rack sprinklers as a smart alternative.
• Rack Storage over 25 ft:
  ✅ For tall racks, if the clearance is more than 10 ft (3.0 m), you must rethink your sprinkler design or use in-rack sprinklers!

🎯 Key Takeaway:

• 🧺 Small gaps = OK with ceiling sprinklers only.
• 🏗️ Large gaps = You may need extra in-rack sprinklers to catch the fire early!
• 🚀 In-rack sprinklers supplement ceiling sprinklers when storage height and clearance create challenges.

✨ Important Note:

When using in-rack sprinklers:
You must install a layer of sprinklers directly below the top tier of stored goods AND at every flue space intersection for maximum coverage!

📋 Table 20.9.4.4 — Plastics and Rubber Commodities (Explained Simply)

Table Title:
▶️ Clearances and In-Rack Sprinkler Options for Plastics and Rubber Storage

What the Table is About:
This table explains how to manage fire protection for **plastics and rubber goods**, which burn much faster and hotter than normal goods. 👉 It shows when you must add in-rack sprinklers or adjust your sprinkler design depending on the storage type and height!

🧹 Breaking Down Each Row:

🧠 What Each Storage Condition Means:

• Palletized / Solid-Piled Storage:
  ✅ 20 ft (6.1 m) clearance allowed, no extra in-rack sprinklers needed.
• Rack Storage up to 25 ft:
  ✅ If clearance to the ceiling is more than 10 ft (3.0 m), either adjust design OR install supplemental in-rack sprinklers as an option.
• Rack Storage over 25 ft:
  ⚠️ In-rack sprinklers are mandatory because plastics/rubbers create very high fire challenges at this height.

🎯 Key Takeaway:

• 🧺 Low storage = manageable with ceiling sprinklers only.
• 🏗️ Medium height = may need in-rack sprinklers to supplement protection.
• 🚀 Tall plastic storage (>25 ft) = in-rack sprinklers are required without exception!

✨ Important Note:

If in-rack sprinklers are required for the actual storage height:
Install quick-response sprinklers directly below the top tier of storage and at every flue space intersection to properly contain fires early! 🔥🛡️

📋 Figure 20.4.8 — Plastics Classification Decision Tree (Explained Simply)

Figure Title:
▶️ How to Classify Plastics for Fire Protection Design

What the Decision Tree is About:
This simple decision tree helps you decide how to classify plastics when designing fire protection systems! 👉 Depending on the plastic type and condition (cartoned, exposed, expanded, etc.), the sprinkler system design changes!

🧩 Step-by-Step Breakdown:

• Plastics are divided into three Groups:
  • Group A — Needs special handling (see below!)
  • Group B — Protect as Class IV commodities
  • Group C — Protect as Class III commodities
• For Group A Plastics:
  ➔ First, check if they are Cartoned or Exposed:
  • Cartoned: Protect using standard rules (Chapters 20-25).
  • Exposed: Then check if they are:
    • Nonexpanded: Protect using parts of Chapters 20-25 for nonexpanded plastics.
    • Expanded: Protect using parts of Chapters 20-25 for expanded plastics (🔥 very dangerous!).
• Free-Flowing Plastics:
  ➔ Treat them like Class IV commodities (higher risk).

🎯 Key Takeaway:

• Group B and C plastics behave like normal Class III/IV materials.
• Group A plastics need detailed evaluation (Cartoned? Exposed? Expanded?) because they are much more dangerous under fire!
• 🔥 Expanded plastics burn fastest and need strongest protection!

✨ Visual Summary:

Plastics ➔ Group A ➔

• Cartoned ➔ Standard protection
• Exposed ➔
  • Nonexpanded ➔ Use nonexpanded rules
  • Expanded ➔ Use expanded rules

Plastics ➔ Group B ➔ Protect as Class IV

Plastics ➔ Group C ➔ Protect as Class III

📋 Table 20.15.2.6 — Hose Stream Allowance and Water Supply Duration (Explained Simply)

Table Title:
▶️ How much water reserve and backup hose stream you need during a fire!

What This Table is About:
When a fire breaks out, sprinklers will work — but firefighters also need backup water streams! 🚒💦 👉 This table tells you how much extra water flow (hose stream) and how long the water supply must last based on what you are protecting.

🧹 How to Understand the Columns:

• Commodity: What is being stored (plastics, tires, paper rolls, etc.)
• Sprinkler Type: CMDA, CMSA, or ESFR sprinklers used
• Sprinkler Spacing Type: Standard or Extended Coverage
• Number of Sprinklers in Design Area: How many sprinklers are considered in the fire design area
• Size of Design Area: How big is the fire area being protected by sprinklers
• Hose Stream Allowance: Extra flow rate needed (in gpm or L/min)
• Water Supply Duration: How long the water needs to keep flowing (in minutes)

🧠 Key Takeaways:

• ✅ Small design areas (up to 1200 ft²) need 250 gpm (950 L/min) of backup water and 60 minutes supply.
• ✅ Larger design areas (up to 2400 ft²) require higher hose stream allowances — up to 500 gpm (1900 L/min) and longer durations.
• ✅ CMSA and ESFR sprinklers usually require slightly more backup water because they are protecting tougher fires.
• ✅ Tire storage and roll paper storage have their own special larger hose stream and longer water supply times because fires are harder to control.

🎯 Practical Example:

• 🏭 Protecting plastics in a warehouse?
• Using CMDA sprinklers and the design area is 1400 ft²?
• ✅ Then you must provide 500 gpm (1900 L/min) hose stream and make sure your water supply lasts 90 minutes!

✨ Notes:

• 🌟 For CMSA and ESFR systems, extra sprinklers needed for obstructions do not count against the number of sprinklers in the design area.
• 🌟 If using portable racks or very tall buildings (up to 30 ft high), water supply duration jumps to 180 minutes for some configurations!

📋 Table 20.17.1.2(a) — CMDA Sprinkler Protection for Indoor Storage of Idle Wood Pallets (Explained Simply)

Table Title:
▶️ Fire Protection Rules for Storing Idle Wood Pallets Indoors

What This Table is About:
Idle wood pallets can catch fire easily! 🔥 This table tells you how to set up **Control Mode Density/Area (CMDA) sprinklers** to properly protect indoor pallet storage based on height and other factors.

🧹 How to Read This Table:

• Type of Sprinkler: Only CMDA sprinklers are considered here.
• Location of Storage: Whether pallets are on the floor or on racks without solid shelves.
• Nominal K-Factor: The size of the sprinkler orifice (higher K = more water flow).
• Maximum Storage Height: How high pallets are allowed to be stacked.
• Maximum Ceiling/Roof Height: How high the building ceiling can be.
• Sprinkler Density: How much water needs to be discharged per square foot.
• Areas of Operation: Size of the area that sprinklers are designed to cover in a fire event.

🧠 Key Points You Should Know:

• ✅ If pallets are stacked up to 6 ft (1.8 m) high, use sprinklers with K-factor 8.0 (115) or bigger. Ceiling height up to 20 ft (6.1 m) is acceptable. Sprinkler density = 0.20 gpm/ft² over 3000 ft² area.
• ✅ If stacking up to 8 ft (2.4 m) high, use a slightly larger sprinkler (K-factor 11.2 or bigger). Ceiling can be up to 30 ft (9.1 m).
• ✅ For storage between 8–20 ft (2.4–6.1 m) high, even bigger sprinklers (K = 11.2 or 16.8) are needed, with ceiling height limits of 30 ft (9.1 m).
• ✅ Higher storage = higher sprinkler density required!

🎯 Quick Summary:

• 🧺 Lower stacks (up to 6 ft) ➔ Lower density (0.20 gpm/ft²) needed.
• 🏗️ Higher stacks ➔ Higher density (up to 0.6 gpm/ft²) needed.
• 🚀 Bigger K-factor sprinklers = Better water flow to control fires faster.

✨ Special Notes:

⭐ If you use sprinklers with K-factor 11.2 (160) or larger, or high-temperature-rated K-8.0 sprinklers, the area of operation can be reduced from 3000 ft² to 2000 ft², making the sprinkler system more efficient!

⭐ Always check the exact required ceiling heights and densities — higher storage and building heights demand stronger sprinkler setups!

📋 Table 20.17.1.2(b) — CMSA Sprinkler Protection for Indoor Storage of Idle Wood Pallets (Explained Simply)

Table Title:
▶️ Using CMSA Sprinklers to Protect Idle Wood Pallet Storage

What This Table is About:
This table shows the sprinkler setup needed for protecting idle wood pallets indoors using CMSA (Control Mode Specific Application) sprinklers — including K-factors, type of system (wet or dry), operating pressures, and design details! 🌟

🧹 How to Read This Table:

• Storage Arrangement: Always “on floor” for this table.
• Commodity Class: Idle wood pallets (high fire load risk).
• Maximum Storage Height: 20 ft (6.1 m) stacking height allowed.
• Maximum Ceiling/Roof Height: Varies based on setup — from 30 ft (9.1 m) to 40 ft (12.2 m).
• K-Factor/Orientation: Sprinkler size and whether Upright or Pendent type is used.
• Type of System: Wet or Dry pipe systems allowed, depending on configuration.
• Number of Design Sprinklers: Usually 15 or 25 sprinklers considered active.
• Minimum Operating Pressure: How much pressure is needed for proper sprinkler performance (psi and bar).

🧠 Key Observations:

• ✅ If you are using a Wet System with 11.2 K Upright Sprinklers, minimum pressure = 15 psi (1.0 bar).
• ✅ Dry Systems need higher design consideration (usually 25 sprinklers in the design area).
• ✅ Higher K-Factor sprinklers (16.8 or 19.6) allow stacking under higher ceiling heights (up to 40 ft / 12.2 m)!
• ✅ Minimum pressures range from 15 psi to 30 psi depending on sprinkler type and ceiling height.

🎯 Quick Summary:

• 🧺 20 ft stacking height = standard.
• 🏗️ Higher K-Factor (16.8 or 19.6) ➔ Higher roof height allowance.
• 🚒 Wet Systems ➔ Easier design (15 sprinklers at 15-16 psi).
• 🚒 Dry Systems ➔ Heavier design (25 sprinklers, always higher operating demands).

✨ Special Notes:

⭐ CMSA sprinklers are designed to control severe fires — perfect for idle pallet storage!
⭐ Always ensure minimum pressure requirements are met at the remote area!

📋 Table 20.17.1.2(c) — ESFR Sprinkler Protection for Indoor Storage of Idle Wood Pallets (Explained Simply)

Table Title:
▶️ Fire Protection Setup Using ESFR Sprinklers for Pallet Storage

What This Table is About:
This table explains how to protect indoor idle wood pallets using **Early Suppression Fast Response (ESFR) sprinklers** — including the required K-factors, ceiling heights, storage heights, and minimum pressures! 🚀

🧹 How to Read This Table:

• Type of Sprinkler: ESFR — pendent (downward facing) or upright (upward facing).
• Location of Storage: Either on the floor or on open racks without solid shelves.
• Nominal K-Factor: Sprinkler size (higher K = bigger water discharge).
• Maximum Storage Height: How high the pallets can be stacked safely.
• Maximum Ceiling/Roof Height: How tall the building roof can be.
• Minimum Operating Pressure: The minimum water pressure needed at the sprinkler head (in psi and bar).

🧠 Key Observations:

• ✅ Using K14.0 (200) ESFR pendent sprinklers:
  • 25 ft storage height, 30 ft roof height, needs 50 psi (3.4 bar) pressure.
  • Higher ceilings (32 ft) require 60 psi (4.1 bar) pressure.
• ✅ With K16.8 (240) sprinklers:
  • Can stack pallets up to 35 ft under 40 ft roofs!
  • Needs around 42–52 psi (2.9–3.6 bar) pressure depending on configuration.
• ✅ Higher K-Factor (22.4 and 25.2) sprinklers allow more flexibility with lower operating pressures (down to 15 psi!).
• ✅ Upright ESFR sprinklers also protect up to 20 ft storage under 30–35 ft ceilings, but may need pressures as high as 75 psi depending on K-factor!

🎯 Quick Summary:

• 🧺 Lower stacking and ceilings ➔ Lower pressure systems (15–35 psi).
• 🏗️ Higher stacking under tall ceilings ➔ Higher K-Factor sprinklers required!
• 🚒 Upright ESFR sprinklers typically need higher pressures (50–75 psi) for the same protection!

✨ Special Notes:

⭐ Always match K-factor, stacking height, ceiling height, and required pressures correctly to avoid sprinkler performance failure!
⭐ Lower pressure systems (like 15 psi) are easier to design but usually involve larger K-factor heads (22.4 or 25.2).