added a "sealed" entry/exit panel (really just a horizontal pipe with a metal

panel overlayed into the middle).   Also, tweaked pipes to always drop the
empty ones.

autoplace.lua

@@ -149,6 +149,28 @@ function pipes_scansurroundings(pos)
 		pzp=1
 	end
 
+-- ...sealed pipe entry/exit...
+
+	if (string.find(nxm.name, "pipeworks:entry_panel") ~= nil)
+	  and (nxm.param2 == 1 or nxm.param2 == 3) then
+		pxm=1
+	end
+
+	if (string.find(nxp.name, "pipeworks:entry_panel") ~= nil)
+	  and (nxp.param2 == 1 or nxp.param2 == 3) then
+		pxp=1
+	end
+
+	if (string.find(nzm.name, "pipeworks:entry_panel") ~= nil)
+	  and (nzm.param2 == 0 or nzm.param2 == 2) then
+		pzm=1
+	end
+
+	if (string.find(nzp.name, "pipeworks:entry_panel") ~= nil)
+	  and (nzp.param2 == 0 or nzp.param2 == 2) then
+		pzp=1
+	end
+
 -- ...pumps, grates, and storage tanks
 
 	if (string.find(nym.name, "pipeworks:storage_tank_") ~= nil) or

devices.lua

@@ -213,6 +213,48 @@ minetest.register_node("pipeworks:spigot", {
 	}
 })
 
+-- sealed pipe entry/exit (decorative horizontal pipe passing through a metal
+-- wall, for use in places where walls should look like they're airtight)
+
+	local airtightboxes = {}
+	pipe_addbox(airtightboxes, pipe_frontstub)
+	pipe_addbox(airtightboxes, pipe_backstub)
+	pipe_addbox(airtightboxes, entry_panel)
+
+minetest.register_node("pipeworks:entry_panel", {
+	description = "Airtight Pipe entry/exit",
+	drawtype = "nodebox",
+	tiles = {
+		"pipeworks_plain.png",
+		"pipeworks_plain.png",
+		"pipeworks_plain.png",
+		"pipeworks_plain.png",
+		"pipeworks_pipe_end_empty.png",
+		"pipeworks_pipe_end_empty.png"
+	},
+	paramtype = "light",
+	paramtype2 = "facedir",
+	groups = {snappy=3, pipe=1},
+	sounds = default.node_sound_wood_defaults(),
+	walkable = true,
+	stack_max = 99,
+	after_place_node = function(pos)
+		pipe_scanforobjects(pos)
+	end,
+	after_dig_node = function(pos)
+		pipe_scanforobjects(pos)
+	end,
+	pipelike=1,
+	on_construct = function(pos)
+	local meta = minetest.env:get_meta(pos)
+	meta:set_int("pipelike",1)
+	end,
+	node_box = {
+		type = "fixed",
+		fixed = airtightboxes,
+	},
+})
+
 -- tanks
 
 for fill = 0, 10 do

init.lua

@@ -121,6 +121,10 @@ spigot_bottomstub = {
 	{ -8/64, -16/64, -3/64, 8/64, -14/64, 3/64 }
 }
 
+entry_panel = {
+	{ -8/16, -8/16, -1/16, 8/16, 8/16, 1/16 }
+}
+
 --  Functions
 
 dbg = function(s)
@@ -307,7 +311,7 @@ for zp = 0, 1 do
 		sounds = default.node_sound_wood_defaults(),
 		walkable = true,
 		stack_max = 99,
-		drop = "pipeworks:pipe_110000_loaded",
+		drop = "pipeworks:pipe_110000_empty",
 		pipelike=1,
 		on_construct = function(pos)
 		local meta = minetest.env:get_meta(pos)